fwiw, I just started experiencing this problem on a device purchased on August 1. After 20 minutes on the phone with Google, they put me in touch with Asus, and after another 20 minutes with them, I receive an RMA#, with a commitment that they'd have it back within 7-10 days, not including shipping _if_ they can replicate it. They also claimed that this is the first they'd heard of this issue.
What a pita. I love my nexus, but if it was Apple I'd have brought it to a genius bar and exchanged it. Next time I'll buy it with Squaretrade