diff --git a/specs/udmf_zdoom.txt b/specs/udmf_zdoom.txt
index 6c2fde91..51329bad 100644
--- a/specs/udmf_zdoom.txt
+++ b/specs/udmf_zdoom.txt
@@ -112,6 +112,7 @@ Note: All <bool> fields default to false unless mentioned otherwise.
       checkswitchrange = <bool>;// Switches can only be activated when vertically reachable.
       blockprojectiles = <bool>;// Line blocks all projectiles
       blockuse = <bool>;		// Line blocks all use actions
+      blocksight = <bool>;		// Line blocks monster line of sight
                     
    }
    
@@ -162,8 +163,8 @@ Note: All <bool> fields default to false unless mentioned otherwise.
       alphafloor = <float>;           // translucency of floor plane (only has meaning with Sector_SetPortal) Default is 1.0.
       alphaceiling = <float>;         // translucency of ceiling plane (only has meaning with Sector_SetPortal) Default is 1.0.
       gravity = <float>;              // Sector's gravity. Default is 1.0.
-      lightcolor = <integer>;         // Sector'S light color as RRGGBB value, default = 0xffffff.
-      fadecolor = <integer>;          // Sector'S fog color as RRGGBB value, default = 0x000000.
+      lightcolor = <integer>;         // Sector's light color as RRGGBB value, default = 0xffffff.
+      fadecolor = <integer>;          // Sector's fog color as RRGGBB value, default = 0x000000.
       desaturation = <float>;         // Color desaturation factor. 0 = none, 1 = full, default = 0.
       silent = <bool>;                // Actors in this sector make no sound,
       nofallingdamage = <bool>;		  // Falling damage is disabled in this sector
@@ -183,12 +184,8 @@ Note: All <bool> fields default to false unless mentioned otherwise.
    
    thing
    {
-      skill# = <bool>			// Unlike the base spec, # can range from 1-8.
-                                // 8 is the maximum amount of skills the skill 
-                                // menu can display.
-      class# = <bool>			// Unlike the base spec, # can range from 1-8.
-                                // 8 is the maximum amount of classes the class
-                                // menu can display.
+      skill# = <bool>			// Unlike the base spec, # can range from 1-16.
+      class# = <bool>			// Unlike the base spec, # can range from 1-16.
 	  conversation = <int>		// Assigns a conversation dialogue to this thing.
 								// Parameter is the conversation ID, 0 meaning none.
 	  countsecret = <bool>;     // Picking up this actor counts as a secret.
@@ -292,6 +289,10 @@ Added 'countsecret' actor property.
 1.15 14.12.2010
 Added vertex floor and ceiling height properties
 
+1.16 23.01.2011
+Added blocksight linedef flag
+Removed remarks of 8 being the maximum number of player classes/skill levels the menu can handle so the spec now properly lists 16 as limit.
+
 ===============================================================================
 EOF
 ===============================================================================
diff --git a/src/actionspecials.h b/src/actionspecials.h
index 8fcb3cf8..0751621f 100644
--- a/src/actionspecials.h
+++ b/src/actionspecials.h
@@ -227,7 +227,7 @@ DEFINE_SPECIAL(Elevator_LowerToNearest, 247, 2, 2, 2)
 DEFINE_SPECIAL(HealThing, 248, 1, 2, 2)
 DEFINE_SPECIAL(Door_CloseWaitOpen, 249, 3, 4, 4)
 DEFINE_SPECIAL(Floor_Donut, 250, 3, 3, 3)
-DEFINE_SPECIAL(FloorAndCeiling_LowerRaise, 251, 3, 3, 3)
+DEFINE_SPECIAL(FloorAndCeiling_LowerRaise, 251, 3, 3, 4)
 DEFINE_SPECIAL(Ceiling_RaiseToNearest, 252, 2, 2, 2)
 DEFINE_SPECIAL(Ceiling_LowerToLowest, 253, 2, 2, 2)
 DEFINE_SPECIAL(Ceiling_LowerToFloor, 254, 2, 2, 2)
diff --git a/src/actor.h b/src/actor.h
index 803acc05..b238e889 100644
--- a/src/actor.h
+++ b/src/actor.h
@@ -325,6 +325,7 @@ enum
 	MF6_ADDITIVEPOISONDAMAGE	= 0x00100000,
 	MF6_ADDITIVEPOISONDURATION	= 0x00200000,
 	MF6_NOMENU			= 0x00400000,	// Player class should not appear in the class selection menu.
+	MF6_BOSSCUBE		= 0x00800000,	// Actor spawned by A_BrainSpit, flagged for timefreeze reasons.
 
 // --- mobj.renderflags ---
 
diff --git a/src/d_iwad.cpp b/src/d_iwad.cpp
index 0999a77e..705ff2f7 100644
--- a/src/d_iwad.cpp
+++ b/src/d_iwad.cpp
@@ -269,6 +269,10 @@ void FIWadManager::ParseIWadInfos(const char *fn)
 		}
 		delete resfile;
 	}
+	if (mIWadNames.Size() == 0 || mIWads.Size() == 0)
+	{
+		I_FatalError("No IWAD definitions found");
+	}
 }
 
 
diff --git a/src/doomdata.h b/src/doomdata.h
index 83345a67..64ac86e5 100644
--- a/src/doomdata.h
+++ b/src/doomdata.h
@@ -152,6 +152,7 @@ enum ELineFlags
 	ML_FIRSTSIDEONLY			= 0x00800000,	// activated only when crossed from front side
 	ML_BLOCKPROJECTILE			= 0x01000000,
 	ML_BLOCKUSE					= 0x02000000,	// blocks all use actions through this line
+	ML_BLOCKSIGHT				= 0x04000000,	// blocks monster line of sight
 };
 
 
diff --git a/src/g_doom/a_bossbrain.cpp b/src/g_doom/a_bossbrain.cpp
index 0110b0ae..d0fb03cb 100644
--- a/src/g_doom/a_bossbrain.cpp
+++ b/src/g_doom/a_bossbrain.cpp
@@ -142,6 +142,7 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_BrainSpit)
 			}
 			// [GZ] Calculates when the projectile will have reached destination
 			spit->special2 += level.maptime;
+			spit->flags6 |= MF6_BOSSCUBE;
 		}
 
 		if (!isdefault)
diff --git a/src/namedef.h b/src/namedef.h
index 52fc87e6..2a3bc3cf 100644
--- a/src/namedef.h
+++ b/src/namedef.h
@@ -443,6 +443,7 @@ xx(smoothlighting)
 xx(blockprojectiles)
 xx(blockuse)
 xx(hidden)
+xx(blocksight)
 
 xx(Renderstyle)
 
diff --git a/src/p_enemy.cpp b/src/p_enemy.cpp
index d0518416..60db3661 100644
--- a/src/p_enemy.cpp
+++ b/src/p_enemy.cpp
@@ -309,7 +309,7 @@ bool P_CheckMissileRange (AActor *actor)
 {
 	fixed_t dist;
 		
-	if (!P_CheckSight (actor, actor->target, SF_SEEPASTBLOCKEVERYTHING|SF_SEEPASTSHOOTABLELINES))
+	if (!P_CheckSight (actor, actor->target, SF_SEEPASTBLOCKEVERYTHING))
 		return false;
 		
 	if (actor->flags & MF_JUSTHIT)
@@ -1151,7 +1151,7 @@ bool P_IsVisible(AActor *lookee, AActor *other, INTBOOL allaround, FLookExParams
 	}
 
 	// P_CheckSight is by far the most expensive operation in here so let's do it last.
-	return P_CheckSight(lookee, other, SF_SEEPASTBLOCKEVERYTHING);
+	return P_CheckSight(lookee, other, SF_SEEPASTSHOOTABLELINES);
 }
 
 //---------------------------------------------------------------------------
diff --git a/src/p_lnspec.cpp b/src/p_lnspec.cpp
index 1b3f627a..88801733 100644
--- a/src/p_lnspec.cpp
+++ b/src/p_lnspec.cpp
@@ -2473,6 +2473,7 @@ FUNC(LS_Line_SetBlocking)
 		ML_BLOCKEVERYTHING,
 		ML_RAILING,
 		ML_BLOCKUSE,
+		ML_BLOCKSIGHT,
 		-1
 	};
 
diff --git a/src/p_map.cpp b/src/p_map.cpp
index 2acb718c..49277e7f 100644
--- a/src/p_map.cpp
+++ b/src/p_map.cpp
@@ -740,7 +740,8 @@ bool PIT_CheckLine (line_t *ld, const FBoundingBox &box, FCheckPosition &tm)
 		// so don't mess around with the z-position
 		if (ld->frontsector->floorplane==ld->backsector->floorplane &&
 			ld->frontsector->floorplane==tm.thing->Sector->floorplane &&
-			!ld->frontsector->e->XFloor.ffloors.Size() && !ld->backsector->e->XFloor.ffloors.Size())
+			!ld->frontsector->e->XFloor.ffloors.Size() && !ld->backsector->e->XFloor.ffloors.Size() &&
+			!open.abovemidtex)
 		{
 			open.bottom=INT_MIN;
 		}
diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index d769f414..f52be1fc 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -299,9 +299,12 @@ void AActor::Serialize (FArchive &arc)
 		<< BlockingLine
 		<< pushfactor
 		<< Species
-		<< Score
-		<< DesignatedTeam
-		<< lastpush << lastbump
+		<< Score;
+	if (SaveVersion >= 3113)
+	{
+		arc << DesignatedTeam;
+	}
+	arc << lastpush << lastbump
 		<< PainThreshold
 		<< DamageFactor
 		<< WeaveIndexXY << WeaveIndexZ
@@ -2747,6 +2750,11 @@ void AActor::Tick ()
 			//Added by MC: Freeze mode.
 			if (bglobal.freeze || level.flags2 & LEVEL2_FROZEN)
 			{
+				// Boss cubes shouldn't be accelerated by timefreeze
+				if (flags6 & MF6_BOSSCUBE)
+				{
+					special2++;
+				}
 				return;
 			}
 		}
@@ -2777,6 +2785,11 @@ void AActor::Tick ()
 
 		if (!(flags5 & MF5_NOTIMEFREEZE))
 		{
+			// Boss cubes shouldn't be accelerated by timefreeze
+			if (flags6 & MF6_BOSSCUBE)
+			{
+				special2++;
+			}
 			//Added by MC: Freeze mode.
 			if (bglobal.freeze && !(player && !player->isbot))
 			{
diff --git a/src/p_sight.cpp b/src/p_sight.cpp
index 359b5d4d..3e699cab 100644
--- a/src/p_sight.cpp
+++ b/src/p_sight.cpp
@@ -256,7 +256,7 @@ bool SightCheck::P_SightCheckLine (line_t *ld)
 	}
 
 	// try to early out the check
-	if (!ld->backsector || !(ld->flags & ML_TWOSIDED))
+	if (!ld->backsector || !(ld->flags & ML_TWOSIDED) || (ld->flags & ML_BLOCKSIGHT))
 		return false;	// stop checking
 
 	// [RH] don't see past block everything lines
diff --git a/src/p_udmf.cpp b/src/p_udmf.cpp
index 72c3cb24..1215d083 100644
--- a/src/p_udmf.cpp
+++ b/src/p_udmf.cpp
@@ -874,6 +874,10 @@ public:
 				Flag(ld->flags, ML_BLOCKUSE, key); 
 				continue;
 
+			case NAME_blocksight:
+				Flag(ld->flags, ML_BLOCKSIGHT, key); 
+				continue;
+
 			default:
 				break;
 			}
diff --git a/src/sdl/i_input.cpp b/src/sdl/i_input.cpp
index 60467366..4f933826 100644
--- a/src/sdl/i_input.cpp
+++ b/src/sdl/i_input.cpp
@@ -21,7 +21,7 @@
 static void I_CheckGUICapture ();
 static void I_CheckNativeMouse ();
 
-static bool GUICapture;
+bool GUICapture;
 static bool NativeMouse = true;
 
 extern int paused;
@@ -36,6 +36,9 @@ EXTERN_CVAR (Bool, fullscreen)
 extern int WaitingForKey, chatmodeon;
 extern constate_e ConsoleState;
 
+extern SDL_Surface *cursorSurface;
+extern SDL_Rect cursorBlit;
+
 static BYTE KeySymToDIK[SDLK_LAST], DownState[SDLK_LAST];
 
 static WORD DIKToKeySym[256] =
@@ -114,6 +117,11 @@ static void I_CheckGUICapture ()
 		GUICapture = wantCapt;
 		if (wantCapt)
 		{
+			int x, y;
+			SDL_GetMouseState (&x, &y);
+			cursorBlit.x = x;
+			cursorBlit.y = y;
+
 			FlushDIKState ();
 			memset (DownState, 0, sizeof(DownState));
 			repeat = !sdl_nokeyrepeat;
@@ -260,15 +268,14 @@ static void I_CheckNativeMouse ()
 	if (wantNative != NativeMouse)
 	{
 		NativeMouse = wantNative;
+		SDL_ShowCursor (wantNative ? cursorSurface == NULL : 0);
 		if (wantNative)
 		{
-			SDL_ShowCursor (1);
 			SDL_WM_GrabInput (SDL_GRAB_OFF);
 			FlushDIKState (KEY_MOUSE1, KEY_MOUSE8);
 		}
 		else
 		{
-			SDL_ShowCursor (0);
 			SDL_WM_GrabInput (SDL_GRAB_ON);
 			CenterMouse ();
 		}
@@ -347,8 +354,8 @@ void MessagePump (const SDL_Event &sev)
 			int x, y;
 			SDL_GetMouseState (&x, &y);
 
-			event.data1 = x;
-			event.data2 = y;
+			cursorBlit.x = event.data1 = x;
+			cursorBlit.y = event.data2 = y;
 			event.type = EV_GUI_Event;
 			if(sev.type == SDL_MOUSEMOTION)
 				event.subtype = EV_GUI_MouseMove;
diff --git a/src/sdl/i_system.cpp b/src/sdl/i_system.cpp
index af717324..49628eef 100644
--- a/src/sdl/i_system.cpp
+++ b/src/sdl/i_system.cpp
@@ -60,6 +60,9 @@
 #include "i_system.h"
 #include "c_dispatch.h"
 #include "templates.h"
+#include "v_palette.h"
+#include "textures.h"
+#include "bitmap.h"
 
 #include "stats.h"
 #include "hardware.h"
@@ -830,7 +833,39 @@ unsigned int I_MakeRNGSeed()
 	return seed;
 }
 
+SDL_Surface *cursorSurface = NULL;
+SDL_Rect cursorBlit = {0, 0, 32, 32};
 bool I_SetCursor(FTexture *cursorpic)
 {
-	return false;
+	if (cursorpic != NULL && cursorpic->UseType != FTexture::TEX_Null)
+	{
+		// Must be no larger than 32x32.
+		if (cursorpic->GetWidth() > 32 || cursorpic->GetHeight() > 32)
+		{
+			return false;
+		}
+
+		if (cursorSurface == NULL)
+			cursorSurface = SDL_CreateRGBSurface (0, 32, 32, 32, MAKEARGB(0,255,0,0), MAKEARGB(0,0,255,0), MAKEARGB(0,0,0,255), MAKEARGB(255,0,0,0));
+
+		SDL_ShowCursor(0);
+		SDL_LockSurface(cursorSurface);
+		BYTE buffer[32*32*4];
+		memset(buffer, 0, 32*32*4);
+		FBitmap bmp(buffer, 32*4, 32, 32);
+		cursorpic->CopyTrueColorPixels(&bmp, 0, 0);
+		memcpy(cursorSurface->pixels, bmp.GetPixels(), 32*32*4);
+		SDL_UnlockSurface(cursorSurface);
+	}
+	else
+	{
+		SDL_ShowCursor(1);
+
+		if (cursorSurface != NULL)
+		{
+			SDL_FreeSurface(cursorSurface);
+			cursorSurface = NULL;
+		}
+	}
+	return true;
 }
diff --git a/src/sdl/sdlvideo.cpp b/src/sdl/sdlvideo.cpp
index b028aafa..efff9470 100644
--- a/src/sdl/sdlvideo.cpp
+++ b/src/sdl/sdlvideo.cpp
@@ -76,6 +76,9 @@ void DoBlending (const PalEntry *from, PalEntry *to, int count, int r, int g, in
 // EXTERNAL DATA DECLARATIONS ----------------------------------------------
 
 extern IVideo *Video;
+extern SDL_Surface *cursorSurface;
+extern SDL_Rect cursorBlit;
+extern bool GUICapture;
 
 EXTERN_CVAR (Float, Gamma)
 
@@ -404,7 +407,13 @@ void SDLFB::Update ()
 	}
 	
 	SDL_UnlockSurface (Screen);
-	
+
+	if (cursorSurface != NULL && GUICapture)
+	{
+		// SDL requires us to draw a surface to get true color cursors.
+		SDL_BlitSurface(cursorSurface, NULL, Screen, &cursorBlit);
+	}
+
 	SDLFlipCycles.Clock();
 	SDL_Flip (Screen);
 	SDLFlipCycles.Unclock();
diff --git a/src/svnrevision.h b/src/svnrevision.h
index 48e8561b..1936c742 100644
--- a/src/svnrevision.h
+++ b/src/svnrevision.h
@@ -3,5 +3,5 @@
 // This file was automatically generated by the
 // updaterevision tool. Do not edit by hand.
 
-#define ZD_SVN_REVISION_STRING "3111"
-#define ZD_SVN_REVISION_NUMBER 3111
+#define ZD_SVN_REVISION_STRING "3121"
+#define ZD_SVN_REVISION_NUMBER 3121
diff --git a/wadsrc/static/menudef.txt b/wadsrc/static/menudef.txt
index e6dabe00..5d448fd2 100644
--- a/wadsrc/static/menudef.txt
+++ b/wadsrc/static/menudef.txt
@@ -528,10 +528,7 @@ OptionMenu "MouseOptions"
 	Option "Enable mouse",				"use_mouse", "YesNo"
 	Option "Enable mouse in menus",	"m_use_mouse", "MenuMouse", "use_mouse"
 	Option "Show back button",		"m_show_backbutton", "Corners", "use_mouse"
-	IfOption(Windows)	// No cursors on SDL right now.
-	{
-		Option "Cursor",				"vid_cursor", "Cursors"
-	}
+	Option "Cursor",				"vid_cursor", "Cursors"
 	StaticText 	""
 	Slider "Overall sensitivity",		"mouse_sensitivity", 0.5, 2.5, 0.1
 	Option "Prescale mouse movement",	"m_noprescale", "NoYes"