Index: source/blender/editors/transform/transform.c
===================================================================
--- source/blender/editors/transform/transform.c	(revision 49518)
+++ source/blender/editors/transform/transform.c	(working copy)
@@ -2933,6 +2933,14 @@
 		
 		for (i = 0, td = t->data; i < t->total; i++, td++)
 			ElementResize(t, td, mat);
+
+		/* In proportional edit it can happen that */
+		/* vertices in the radius of the brush end */
+		/* outside the clipping area               */
+		/* XXX HACK - dg */
+		if(t->flag & (T_PROP_EDIT | T_PROP_CONNECTED)) {
+			clipUVData(t);
+		}
 	}
 	
 	recalcData(t);
@@ -3788,9 +3796,18 @@
 	applyTranslation(t, t->values);
 
 	/* evil hack - redo translation if clipping needed */
-	if (t->flag & T_CLIP_UV && clipUVTransform(t, t->values, 0))
+	if (t->flag & T_CLIP_UV && clipUVTransform(t, t->values, 0)) {
 		applyTranslation(t, t->values);
 
+		/* In proportional edit it can happen that */
+		/* vertices in the radius of the brush end */
+		/* outside the clipping area               */
+		/* XXX HACK - dg */
+		if(t->flag & (T_PROP_EDIT | T_PROP_CONNECTED)) {
+			clipUVData(t);
+		}
+	}
+
 	recalcData(t);
 
 	ED_area_headerprint(t->sa, str);
Index: source/blender/editors/transform/transform.h
===================================================================
--- source/blender/editors/transform/transform.h	(revision 49518)
+++ source/blender/editors/transform/transform.h	(working copy)
@@ -562,6 +562,7 @@
 void flushTransUVs(TransInfo *t);
 void flushTransParticles(TransInfo *t);
 int clipUVTransform(TransInfo *t, float *vec, int resize);
+void clipUVData(TransInfo *t);
 void flushTransNodes(TransInfo *t);
 void flushTransSeq(TransInfo *t);
 void flushTransTracking(TransInfo *t);
Index: source/blender/editors/transform/transform_conversions.c
===================================================================
--- source/blender/editors/transform/transform_conversions.c	(revision 49518)
+++ source/blender/editors/transform/transform_conversions.c	(working copy)
@@ -2493,6 +2493,26 @@
 	return (clipx || clipy);
 }
 
+void clipUVData(TransInfo *t)
+{
+	TransData *td = NULL;
+	int a;
+	float aspx, aspy;
+
+	ED_space_image_get_uv_aspect(t->sa->spacedata.first, &aspx, &aspy);
+
+	for (a = 0, td = t->data; a < t->total; a++, td++) {
+		if (td->flag & TD_NOACTION)
+			break;
+
+		if ((td->flag & TD_SKIP) || (!td->loc))
+			continue;
+
+		td->loc[0] = MIN2(MAX2(0.0f, td->loc[0]), aspx);
+		td->loc[1] = MIN2(MAX2(0.0f, td->loc[1]), aspy);
+	}
+}
+
 /* ********************* ANIMATION EDITORS (GENERAL) ************************* */
 
 /* This function tests if a point is on the "mouse" side of the cursor/frame-marking */