Hi, If you are still looking for an answer, Heres wht you need to do.
1, connect your ipod to a computer with itunes
2, Hold the home button and power/lock button untill you get a screen that has "itunes" on it with a usb. do not slide to power off.
If you can back up your data, do it
4.Click the device on Itunes and click "Restore Ipod"
5. Click "Update and restore"
It will update to IOS 3.1.3 then restore your ipod.
I dont think there is a way to do this without restoring the data
hope this helps