I finally got my usb data cable and downloaded BITPIM. I sucessfully tranferred one song to my phone as a ringtone. After that, I added another song. In attempt in changing my ringtone, everytime I go to setting&tools > call sounds > call ringtone, and any selection after that (ie Caller ID/No Caller ID/Restrict Calls/All Calls), my phone restarts on it's own.

After that, I tried removing whatever songs I previously uploaded via usb. Still, my phone restarts after going through the CALL SOUNDS menu.

Any help would be appreciated! Thanks.