I have the same problem. But I read somewhere were a wipe and fresh OS install fixes the problem. I'm still trying out so I don't have things on the storm that I don't already have on the curve which is backed up regularly.
Thanks rweckhoff, I didn't know about the memory cleaning option!
Well, I finally figured out what was broken. Nothing to do with KeyStoreManager. I think KeyStoreManager was the last SUCCESSFUL db to backup, and the next one on the list was causing the problem (which I couldn't see).
Ended up being the newest BB Keepass addon. I just removed that, and everything backed up fine.