I don't have the yellow blotches, the bottom left corner signal drop is something I think I can live with by holding the phone differently, my proximity sensor doesn't seem to be a problem but my GPS doesn't work. It thinks I'm about 200 miles east of where I actually am. Location on wifi only is fine (my router is registered with Skyhook). I've reset network settings, toggled airplane mode,done a reset and restore. Any other ideas?