Restore your iPad but not from a backup as you may re introduce the problem all over again.
You may want to sync maybe 5 apps at a time after the restore, then test the iPad. Might be one app that's the culprit.
It happens to me from time to time and IMO it is a result of memory issues. I reboot my iPad every couple of days on average. I think that just by restarting the device on ocassion you help clear the memory and it seems to keep my iPad from "crashing" often. When you reboot, you are merely resetting the device and again ... IMO ... it's not a bad habit to get into with the iPad.
This is my simple solution. You may have apps or corrupt data that could be causing problems as well. But a restart can't hurt and I think it's a good practice to maintain. I'm sure there are those who will disagree!!