My two cents here: I'm experiencing the same problem. I've noticed there was a problem earlier in the boot process where the kernel was crying about a deadlock in radeon power management.

I opened a bug and I'm bisecting the kernel right now ( https://bugzilla.kernel.org/show_bug.cgi?id=42639).

It may or may not be related, but both problems appeared when moving to 3.3-rc1.

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Alexandre Demers