Mac OS X 10.4: Software Update "The digital signature for this package is incorrect" alert

If you encounter the message "The digital signature for this package is incorrect" while using Software Update in Mac OS X 10.4 Tiger, try the following steps:

1. Quit Software Update.
2. Restart your Mac.
3. Open Software Update.
4. Deselect all available updates, except for any Mac OS X 10.4.x Update.
5. Install the Mac OS X 10.4.x Update, if available (it should install), and restart.
6. Open Software Update, and install any remaining updates.

If the issue occurs while attempting the Mac OS X 10.4.x Update, download the update from Apple Downloads and manually install it. After restarting, try using Software Update to install any remaining updates.

This document will be updated as more information becomes available.