You could try a factory reset if your out of options.
pull the battery out and reinsert it
Hold the Volume Down button
Press and release the Power button
You are now presented with a menu that allows for Fastbook, Recovery, Clear Storage, and Simlock
Select Clear Storage by pressing the Volume Down button
Press and release the Power button
Now simply confirm your decision: Volume Up for YES and Volume Down for NO
If you selected YES, all data including third-party applications will be deleted from the Samsung Galaxy S. Once the wipe is complete, the phone will reboot to its factory fresh state.
