A number of users have reported that virtually all third-party applications crash soon after launching under iPhone OS 2.2.1. Fortunately, an extremely simple fix works in many instances of this problem:
- Touch and hold any application icon the icons begin to shake.
- Tap the "x" in the corner of the application you want to delete.
- Tap Delete.
- Press the Home button.
- Download the application again, either from your iPhone or your desktop computer (there will be no additional charge for the redownload)