Hi, my friend had a simliar problem with his Visor Basic. Try doing a hard-reset. This will wipe your RAM clean, so you'll lose all your data. If you can't even sync your data, buy a back-up or flash module (not too much $$$ anymore) and back it up to that then hard reset.
Hope i was of some help, if that doesn't work, talk to me on aim or icq.