Samsung Galaxy Spica won't boot up fully. Just restarts over and over

My Samsung galaxy won't turn on properly. Basically it turns on, shows the 'OMG screen' which it does when it crashes, then goes to the Samsung loading bar, but then goes back to the crash screen. It keeps going in a loop forever! I tried a hard reset, which if I understand correctly is holding down the volume down key and end call key, but this did nothing. (Sorry I'm not good at describing, hope this is clear!) Thanks!