Mac OS X 10.5: Using Time Machine and troubleshooting Time Machine issues

Issue: Using Time Machine alert messages to troubleshoot backup issues.
Solution: See Time Machine: Troubleshooting backup issues.

Issue: How can Time Machine be used to recover lost or accidentally deleted files?
Solution: See Mac OS X 10.5 Help: Recovering items using Time Machine and Spotlight.

Issue: In the Time Machine "time travel" window, past backups may not appear.
Solution: See Mac OS X 10.5: Time Machine backups are not visible.

Issue: After 10 GB or more of data is backed up, Time Machine may stop backing up.
Solution: See Mac OS X 10.5: Time Machine stops backing up to external disk.

Issue: A Time Machine back up performed while Aperture is running may lead to inconsistencies in the Aperture database.
Solution: See Aperture: Set Time Machine to exclude Aperture library from automatic backups.

Issue: How can Time Machine be used to revert to a previous version of Mac OS X 10.5?
Solution: See Mac OS X 10.5 Help: Reverting to a previous Mac OS X version.

Issue: Time Machine doesn't back up to AirPort Disks.
Solution: See Mac OS X 10.5: Time Machine doesn't back up to AirPort Disks.

Issue: Time Machine may display "Preparing" for a longer time.
Solution: See Mac OS X 10.5: Time Machine may display "Preparing" for a longer time.