Index: source/blender/blenkernel/intern/cdderivedmesh.c
===================================================================
--- source/blender/blenkernel/intern/cdderivedmesh.c	(revision 36228)
+++ source/blender/blenkernel/intern/cdderivedmesh.c	(working copy)
@@ -1192,6 +1192,12 @@
 					}
 				}
 				if(!dodraw) {
+					curface++;
+					if(mface->v4)
+					{
+						curface++;
+						i++;
+					}
 					continue;
 				}