To restore your iPad from a newer version (beta, perhaps?) of iOS to a previous version of the OS (such as 3.2.2, the latest release), do the following:
- Connect your iPad to your computer
- Open iTunes
- On the left side, select your iPad under Devices
- On the Summary view for your iPad, option-click Restore
- Browse to
~/Library/iTunes/iPad Software Updatesand select the .ipsw file (it should say 3.2.2 somewhere in the filename)
Update: If you’ve lost the old .ipsw file for 3.2.2, you can download it from Apple at this link.