diff --git a/docs/rh-log.txt b/docs/rh-log.txt
index a6c0e064a..9f444321c 100644
--- a/docs/rh-log.txt
+++ b/docs/rh-log.txt
@@ -1,4 +1,11 @@
-March 28, 2009  (Changes by Graf Zahl)
+March 29, 2009  (Changes by Graf Zahl)
+- Fixed: Altering a link type with Sector_SetLink did not work.
+- Fixed: player.crouchsprite had no proper means of unsetting the crouch
+  sprite which is needed by the ChexPlayer.
+- Fixed: A_ChangeFlags must unlink the actor from the world before changing
+  the NOBLOCKMAP and NOSECTOR flags.
+
+March 28, 2009  (Changes by Graf Zahl)
 - Fixed: Dehacked string replacement did not check the clusters' finaleflats.
 - Changed the definition of several typedef'd structs so that they are
   properly named.
diff --git a/src/p_linkedsectors.cpp b/src/p_linkedsectors.cpp
index ac75f472e..4fa4a699d 100644
--- a/src/p_linkedsectors.cpp
+++ b/src/p_linkedsectors.cpp
@@ -51,6 +51,9 @@ enum
 	LINK_CEILINGMIRROR=10,
 	LINK_BOTHMIRROR=15,
 
+	LINK_FLOORBITS=5,
+	LINK_CEILINGBITS=10,
+
 	LINK_FLAGMASK = 15
 
 };
@@ -236,26 +239,20 @@ void P_StartLinkedSectorInterpolations(TArray<DInterpolation *> &list, sector_t
 static void AddSingleSector(extsector_t::linked::plane &scrollplane, sector_t *sector, int movetype)
 {
 	// First we have to check the list if the sector is already in it
-	// If so the move type may have to be adjusted or the link to be removed
+	// If so the move type must be adjusted
 
 	for(unsigned i = 0; i < scrollplane.Sectors.Size(); i++)
 	{
 		if (scrollplane.Sectors[i].Sector == sector)
 		{
-			int oldtype = scrollplane.Sectors[i].Type;
-
-			if ((oldtype & (LINK_FLOOR|LINK_FLOORMIRROR)) && 
-				(movetype & (LINK_FLOORMIRROR|LINK_FLOOR)))
+			if (movetype & LINK_FLOORBITS)
 			{
-				// Invalid combination for floor.
-				movetype &= ~(LINK_FLOOR + LINK_FLOORMIRROR);
+				scrollplane.Sectors[i].Type &= ~LINK_FLOORBITS;
 			}
 
-			if ((oldtype & (LINK_CEILING|LINK_CEILINGMIRROR)) && 
-				(movetype == LINK_CEILINGMIRROR || movetype == LINK_CEILING))
+			if (movetype & LINK_CEILINGBITS)
 			{
-				// Invalid combination for CEILING.
-				movetype &= ~(LINK_CEILING + LINK_CEILINGMIRROR);
+				scrollplane.Sectors[i].Type &= ~LINK_CEILINGBITS;
 			}
 
 			scrollplane.Sectors[i].Type |= movetype;
diff --git a/src/thingdef/thingdef_codeptr.cpp b/src/thingdef/thingdef_codeptr.cpp
index f63441416..0fd476a44 100644
--- a/src/thingdef/thingdef_codeptr.cpp
+++ b/src/thingdef/thingdef_codeptr.cpp
@@ -2298,16 +2298,23 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_ChangeFlag)
 	if (fd != NULL)
 	{
 		bool kill_before, kill_after;
+		INTBOOL item_before, item_after;
 
 		kill_before = self->CountsAsKill();
+		item_before = self->flags & MF_COUNTITEM;
+
 		if (fd->structoffset == -1)
 		{
 			HandleDeprecatedFlags(self, cls->ActorInfo, expression, fd->flagbit);
 		}
 		else
 		{
-			int *flagp = (int*) (((char*)self) + fd->structoffset);
+			DWORD *flagp = (DWORD*) (((char*)self) + fd->structoffset);
 
+			// If these 2 flags get changed we need to update the blockmap and sector links.
+			bool linkchange = flagp == &self->flags && (fd->flagbit == MF_NOBLOCKMAP || fd->flagbit == MF_NOSECTOR);
+
+			if (linkchange) self->UnlinkFromWorld();
 			if (expression)
 			{
 				*flagp |= fd->flagbit;
@@ -2316,8 +2323,10 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_ChangeFlag)
 			{
 				*flagp &= ~fd->flagbit;
 			}
+			if (linkchange) self->LinkToWorld();
 		}
 		kill_after = self->CountsAsKill();
+		item_after = self->flags & MF_COUNTITEM;
 		// Was this monster previously worth a kill but no longer is?
 		// Or vice versa?
 		if (kill_before != kill_after)
@@ -2331,6 +2340,18 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_ChangeFlag)
 				level.total_monsters--;
 			}
 		}
+		// same for items
+		if (item_before != item_after)
+		{
+			if (item_after)
+			{ // It counts as an item now.
+				level.total_items++;
+			}
+			else
+			{ // It no longer counts as an item
+				level.total_items--;
+			}
+		}
 	}
 	else
 	{
diff --git a/src/thingdef/thingdef_properties.cpp b/src/thingdef/thingdef_properties.cpp
index f08e5ed9b..65b527100 100644
--- a/src/thingdef/thingdef_properties.cpp
+++ b/src/thingdef/thingdef_properties.cpp
@@ -1776,7 +1776,18 @@ DEFINE_CLASS_PROPERTY_PREFIX(player, scoreicon, S, PlayerPawn)
 DEFINE_CLASS_PROPERTY_PREFIX(player, crouchsprite, S, PlayerPawn)
 {
 	PROP_STRING_PARM(z, 0);
-	defaults->crouchsprite = GetSpriteIndex (z);
+	if (strlen(z) == 4)
+	{
+		defaults->crouchsprite = GetSpriteIndex (z);
+	}
+	else if (*z == 0)
+	{
+		defaults->crouchsprite = 0;
+	}
+	else
+	{
+		I_Error("Sprite name must have exactly 4 characters");
+	}
 }
 
 //==========================================================================