diff --git a/source/blender/blenkernel/intern/node_composite.c b/source/blender/blenkernel/intern/node_composite.c
index 7f957d4d943..49166a1a131 100644
--- a/source/blender/blenkernel/intern/node_composite.c
+++ b/source/blender/blenkernel/intern/node_composite.c
@@ -1000,36 +1000,40 @@ static void node_composit_exec_rlayers(void *data, bNode *node, bNodeStack **in,
 					stackbuf= alloc_compbuf(rr->rectx, rr->recty, CB_RGBA, 0);
 					stackbuf->rect= rl->rectf;
 				}
-				
-				stackbuf->xof= rr->xof;
-				stackbuf->yof= rr->yof;
-				
-				/* put on stack */	
-				out[RRES_OUT_IMAGE]->data= stackbuf;
-				
-				if(out[RRES_OUT_ALPHA]->hasoutput)
-					out[RRES_OUT_ALPHA]->data= valbuf_from_rgbabuf(stackbuf, CHAN_A);
-				if(out[RRES_OUT_Z]->hasoutput)
-					out[RRES_OUT_Z]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_Z);
-				if(out[RRES_OUT_VEC]->hasoutput)
-					out[RRES_OUT_VEC]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_VECTOR);
-				if(out[RRES_OUT_NOR]->hasoutput)
-					out[RRES_OUT_NOR]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_NORMAL);
-	/*			
-				if(out[RRES_OUT_COL]->hasoutput)
-					out[RRES_OUT_COL]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_RGBA);
-				if(out[RRES_OUT_DIFF]->hasoutput)
-					out[RRES_OUT_DIFF]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_DIFFUSE);
-				if(out[RRES_OUT_SPEC]->hasoutput)
-					out[RRES_OUT_SPEC]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_SPEC);
-				if(out[RRES_OUT_SHAD]->hasoutput)
-					out[RRES_OUT_SHAD]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_SHADOW);
-				if(out[RRES_OUT_AO]->hasoutput)
-					out[RRES_OUT_AO]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_AO);
-				if(out[RRES_OUT_RAY]->hasoutput)
-					out[RRES_OUT_RAY]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_RAY);
-	*/			
-				generate_preview(node, stackbuf);
+				if(stackbuf==NULL) {
+					printf("Error; Preview Panel in UV Window returns zero sized image\n");
+				}
+				else {
+					stackbuf->xof= rr->xof;
+					stackbuf->yof= rr->yof;
+					
+					/* put on stack */	
+					out[RRES_OUT_IMAGE]->data= stackbuf;
+					
+					if(out[RRES_OUT_ALPHA]->hasoutput)
+						out[RRES_OUT_ALPHA]->data= valbuf_from_rgbabuf(stackbuf, CHAN_A);
+					if(out[RRES_OUT_Z]->hasoutput)
+						out[RRES_OUT_Z]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_Z);
+					if(out[RRES_OUT_VEC]->hasoutput)
+						out[RRES_OUT_VEC]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_VECTOR);
+					if(out[RRES_OUT_NOR]->hasoutput)
+						out[RRES_OUT_NOR]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_NORMAL);
+		/*			
+					if(out[RRES_OUT_COL]->hasoutput)
+						out[RRES_OUT_COL]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_RGBA);
+					if(out[RRES_OUT_DIFF]->hasoutput)
+						out[RRES_OUT_DIFF]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_DIFFUSE);
+					if(out[RRES_OUT_SPEC]->hasoutput)
+						out[RRES_OUT_SPEC]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_SPEC);
+					if(out[RRES_OUT_SHAD]->hasoutput)
+						out[RRES_OUT_SHAD]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_SHADOW);
+					if(out[RRES_OUT_AO]->hasoutput)
+						out[RRES_OUT_AO]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_AO);
+					if(out[RRES_OUT_RAY]->hasoutput)
+						out[RRES_OUT_RAY]->data= compbuf_from_pass(rd, rl, rr->rectx, rr->recty, SCE_PASS_RAY);
+		*/			
+					generate_preview(node, stackbuf);
+				}
 			}
 		}
 	}	
diff --git a/source/blender/src/drawimage.c b/source/blender/src/drawimage.c
index 516a1e2b8f3..2a046a30be2 100644
--- a/source/blender/src/drawimage.c
+++ b/source/blender/src/drawimage.c
@@ -1308,6 +1308,7 @@ static void image_panel_preview(ScrArea *sa, short cntrl)	// IMAGE_HANDLER_PREVI
 	
 	if(is_preview_allowed(sa)==0) {
 		rem_blockhandler(sa, IMAGE_HANDLER_PREVIEW);
+		G.scene->r.scemode &= ~R_COMP_CROP;	/* quite weak */
 		return;
 	}