diff --git a/engine/client/cl_main.c b/engine/client/cl_main.c
index 21bf0f7f7..01afa096e 100644
--- a/engine/client/cl_main.c
+++ b/engine/client/cl_main.c
@@ -6383,6 +6383,8 @@ double Host_Frame (double time)
 			cl.playerview[i].audio.reverbtype = 0;
 			VectorClear(cl.playerview[i].audio.velocity);
 		}
+		if (cls.state && r_worldentity.model && r_worldentity.model->loadstate == MLS_NOTLOADED)
+			Mod_LoadModel(cl.worldmodel, MLV_WARNSYNC);
 
 		if (SCR_UpdateScreen && !vid.isminimized)
 		{
diff --git a/engine/client/image.c b/engine/client/image.c
index 6db0547b8..6a5cbd6cd 100644
--- a/engine/client/image.c
+++ b/engine/client/image.c
@@ -37,14 +37,8 @@ cvar_t r_dodgytgafiles = CVARD("r_dodgytgafiles", "0", "Many old glquake engines
 cvar_t r_dodgypcxfiles = CVARD("r_dodgypcxfiles", "0", "When enabled, this will ignore the palette stored within pcx files, for compatibility with quake2.");
 #endif
 cvar_t r_dodgymiptex = CVARD("r_dodgymiptex", "1", "When enabled, this will force regeneration of mipmaps, discarding mips1-4 like glquake did. This may eg solve fullbright issues with some maps, but may reduce distant detail levels.");
-static void QDECL R_Image_BuggyCvar (struct cvar_s *var, char *oldvalue)
-{	//force these cvars to value 1 if they're empty.
-	//cvars using this should be changed to 0 by default, once our engine bugs are debugged/fixed.
-	if (!*var->string)
-		var->ival = var->value = true;
-}
-cvar_t r_keepimages = CVARCD("r_keepimages", "", R_Image_BuggyCvar, "Retain unused images in memory for slightly faster map loading. FIXME: a setting of 0 may be crashy! (empty is treated as 1 for now).\n0: Redundant images will be purged after each map change.\n1: Images will be retained until vid_reload (potentially consuming a lot of ram).");
-cvar_t r_ignoremapprefixes = CVARCD("r_ignoremapprefixes", "", R_Image_BuggyCvar, "Ignores when textures were loaded from map-specific paths. FIXME: empty is currently interpretted as 1 because the alternative is too memory hungary with r_keepimages 1.");
+cvar_t r_keepimages = CVARD("r_keepimages", "0", "Retain unused images in memory for slightly faster map loading.\n0: Redundant images will be purged after each map change.\n1: Images will be retained until vid_reload (potentially consuming a lot of ram).");
+cvar_t r_ignoremapprefixes = CVARD("r_ignoremapprefixes", "0",  "Ignores when textures were loaded from map-specific paths.\n0: textures/foo/tex.tga will not be confused with textures/foo/tex.tga.\n1: The same texture might be loaded multiple times over.");
 
 char *r_defaultimageextensions =
 #ifdef IMAGEFMT_DDS
diff --git a/engine/gl/gl_model.c b/engine/gl/gl_model.c
index dfde7b772..e4671d323 100644
--- a/engine/gl/gl_model.c
+++ b/engine/gl/gl_model.c
@@ -505,15 +505,18 @@ qboolean Mod_PurgeModel(model_t	*mod, enum mod_purge_e ptype)
 
 #ifdef TERRAIN
 	//we can safely flush all terrain sections at any time
-	if (mod->terrain && ptype != MP_MAPCHANGED)
+	if (mod->terrain)
+	{
+		if (ptype == MP_MAPCHANGED)
+			return false;	//don't destroy any data there that the user might want to save. FIXME: handle better.
 		Terr_PurgeTerrainModel(mod, false, true);
+	}
 #endif
 
 	//purge any vbos
 	if (mod->type == mod_brush)
 	{
-		//brush models cannot be safely flushed.
-		if (ptype != MP_RESET)
+		if (ptype == MP_FLUSH)
 			return false;
 #ifndef SERVERONLY
 		Surf_Clear(mod);
@@ -522,12 +525,7 @@ qboolean Mod_PurgeModel(model_t	*mod, enum mod_purge_e ptype)
 
 #ifdef TERRAIN
 	if (mod->type == mod_brush || mod->type == mod_heightmap)
-	{
-		//heightmap/terrain models cannot be safely flushed (brush models might have terrain embedded).
-		if (ptype != MP_RESET)
-			return false;
 		Terr_FreeModel(mod);
-	}
 #endif
 	if (mod->type == mod_alias)
 	{
@@ -1004,6 +1002,8 @@ void Mod_ModelLoaded(void *ctx, void *data, size_t a, size_t b)
 	if (mod->type == mod_brush)
 	{
 		Surf_BuildModelLightmaps(mod);
+		r_oldviewcluster = -1;	//just in case.
+		r_oldviewcluster2 = -2;
 	}
 	if (mod->type == mod_sprite)
 	{
diff --git a/engine/gl/gl_rlight.c b/engine/gl/gl_rlight.c
index 437fcf9dc..819e248e5 100644
--- a/engine/gl/gl_rlight.c
+++ b/engine/gl/gl_rlight.c
@@ -737,13 +737,16 @@ void R_PushDlights (void)
 		return;
 #endif
 
-	if (r_dynamic.ival <= 0|| !cl.worldmodel)
+	if (r_dynamic.ival <= 0|| !r_worldentity.model)
 		return;
 
-	if (!cl.worldmodel->nodes)
+	if (r_worldentity.model->loadstate != MLS_LOADED)
 		return;
 
-	currentmodel = cl.worldmodel;
+	if (!r_worldentity.model->nodes)
+		return;
+
+	currentmodel = r_worldentity.model;
 	if (!currentmodel->funcs.MarkLights)
 		return;
 	
diff --git a/engine/server/sv_main.c b/engine/server/sv_main.c
index c06ee2f2d..75954757f 100644
--- a/engine/server/sv_main.c
+++ b/engine/server/sv_main.c
@@ -5309,6 +5309,10 @@ float SV_Frame (void)
 		if (sv.state < ss_active)	//whoops...
 			return delay;
 
+		//make sure the worldmodel is actually valid...
+		if (sv.world.worldmodel && sv.world.worldmodel->loadstate != MLS_LOADED)
+			Mod_LoadModel(sv.world.worldmodel, MLV_ERROR);
+
 		SV_CheckVars ();
 
 // send messages back to the clients that had packets read this frame