In any case, killexchange lock still worked for me with os 3, with the once a day thing.

the new exchangeunlock on cydia works great though, with no once a day issues

“A thread on the Apple discussions boards (http://discussions.apple.com/thread.jspa?threadID=2045901&start=0&tstart=0) points to the answer. Since the ActiveSync link to the Exchange server controls some security policies on the phone, you need to refresh those controls; the easiest way to do that, short of deleting and recreating the Exchange account, is to turn off all three sync modes and the Push setting. Once that’s done, you can go back to the passcode lock screen and disable the lock or adjust the timeout. Put your sync settings back the way they were and your changes to the passcode config should remain in place.”