The Basic Troubleshooting Steps are:
Restart.. Reset.. Restore from Backup.. Restore as New...
Try a Reset of the Touch... You will Not Lose Any Data...
Turn the Touch Off... ( if it isn’t already )
Press and Hold the Sleep/Wake Button and the Home Button at the Same Time...
Wait for the Apple logo to Appear and then Disappear...
Usually takes about 15 - 20 Seconds... (But can take Longer...)
Release the Buttons...
Turn the Touch On...
If that does not help... See Here:
Backing up, Updating and Restoring
Reset iPod touch: Press and hold the On/Off Sleep/Wake button and the Home
button at the same time for at least ten seconds, until the Apple logo appears.
- Restore from backup
- Restore to factory defaults/new iPod
If you still have the problem you likey have a hardware problem and an appointment at the Genius Bar of an Apple store is in order.