I'm having the same problem
I used LeeDroid rom, and though it was it's fault.
Then I installed InsertCoin 7.3.0. It still happens.
I'm quite sure it's not a hardware problem because it goes away after a restart even if I don't move the phone at all.
Sometimes a restart doesn't help, but restarting to recovery and rebooting always seem to solve it for a while
My current guess it it might be some app that causes this
Any news anyone?