I'm running 2.2 on my Galaxy S. One day for no reason I can figure, my SMS messages would say 'sending' but never actually send. If I delete the message and try to resend it two more times, the third time it will send normally. This only occurs after the first time I try to send an SMS after rebooting. The problem doesn't happen again until the next reboot. BTW it doesnt seem to have anything to do with the carrier I'm using because I switched to a different one with a different SIM and the problem persisted.