I've also noticed that from time to time applications crash or restart. Don't know if it because of jb because it happened to me in the past on non jb device - maybe it's ios 5.0.1 related problem.
Greywolf, Isn't it possible that the JB could be indirectly responsible for an unstable system - due, perhaps, to a rogue app that was installed from outside Apple Store? Or course, I'm sure there are apps available from the Apple Store that could mess things up some too. Brian - Sent from my iPad using iPF
I had the same problem until I installed "Crash Reporter" and looked at the crash logs. It's usually a mobile substrate extension or spp that relies on it that causes the crash. Look at the log and determine which cydia app comes up in the crash log and remove it that helped me. For me this helped a ton.