I'm reading a few reports of iCaughtU Pro causing this 'crash on incomming SMS' thing.
Some saying its causing the Native SMS client problems and some saying its crashing Bite SMS.
In all cases the removal of iCaughtU Pro stops the crashing, and I must say after uninstalling it myself an hour ago AND 3 SMS received with no crash,
In beginning to believe I've found the conflict.
Now it's worth also saying that I updated iCaughtU Pro to the latest ver, and didn't have any problems when I was on iOS 5.1.0
These springbord crash to safemode problems only started after I updated the iOS to 5.1.1 and Jailbroke 4 mins later.
I'll report back if I find anything new.
Hopfully my info may help others, not just members of this forum but people who find their way here
Via a google search of the problem as I did. Fingers crossed