Apple's Tech Support

• Jailbreaking your iPod touch nullifies your warranty with Apple. Contacting Apple for a frozen and jailbroken iPod Touch won't help you. Once you alert them that the iPod Touch is jailbroken, you no longer get assistance from them. You need to fix the freezing issues on your own using a factory restore.
  
  

Fixing Frozen iPod With Factory Restore

• The factory restore is the most effective way to fix a frozen iPod Touch and remove the jailbreak causing the problem. Factory restore eliminates all your custom settings, files, applications, music and photos from your iPod touch returning it to original stock condition. This process also removes the jailbreak causing the freezing problem.
  
  

Recovery Mode

• The factory-restore process begins with putting your iPod Touch into Recovery mode. Open iTunes on your computer. Plug your iPod Touch into your personal computer using the USB cord that came with the device. Place your iPod into recovery mode by holding the "Home" button and "Sleep/Wake" button on your iPod at the same time for ten seconds. Release the Sleep/Wake button. Continue to hold the "Home" button until a dialog box appears in iTunes alerting you to an iPod in recovery mode.
  
  

Factory Restore

• The error box in iTunes gives you the option to start the restoration process. Click the button to restore your iPod Touch to factory conditions. ITunes wipes your iPod Touch clean, removing the jailbreak and fixing the freezing issue. Once your iPod is clean, iTunes lets you install a backup of your device to regain your applications, music and photos. At this point, you can choose to rejailbreak your device or continue with a locked iPod Touch.