11-27-2012 06:21 PM
Hi and Welcome to the Community!
I recommend that you attempt to boot into Safe Mode:
It may take you multiple attempts to get the ESC key sequence (press/release/hold) correct, so be patient. When successfully into Safe Mode, think carefully...what happened just before this behavior started? A new app? An update? A Theme? Something else? Think carefully as the smallest change could be causal...and attempt to undo whatever that was.
Failing that, it will be a matter of figuring out why...here is a process that might help narrow it down:
When the behavior presents, you know the culprit...the last thing you loaded.
If the behavior does not re-present, then you know that either step 1 or 2 cured it.
If the behavior presents no matter what, then you likely have a hardware level issue for which no amount of OS or software can cure.
Good luck and let us know!