Then the odds are very good that you have a jail break tweak installed that is incompatible with your iPad, your iOS (5.1.1) or both.
So, has this behavior always happened or just recently. If just recently, think back to the tweaks you installed before this behavior began. Then, go back to Cydia and remove those tweaks. If the behavior then stops, it definitely was one of those. Then, you can re-install them one at a time and see which one causes the trouble.
If you can't figure out which one it is, go ahead and list out your installed jail break tweaks. Maybe we can look through the list and see which one(s) might be causing the issue.
Marilyn
P.S. And, since you're talking about a jail broken iPad, I've taken the liberty of moving your post over to the Hacking section. Thanks for your understanding.