After switching to a testing build of 3.9 kernel, this problem is gone. $ uname -a Linux 3.9.0-030900rc8-generic #201304211835 SMP Sun Apr 21 22:35:53 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
After switching to a testing build of 3.9 kernel, this problem is gone. -generic #201304211835 SMP Sun Apr 21 22:35:53 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
$ uname -a
Linux 3.9.0-030900rc8