Time Machine advisory [UPDATE]

People have been posting in Apple's discussion boards of having problems with using Leopard's backup utility, Time Machine. Some of the problems encountered, which includes stalled backups, may be due to the backup drive's partitioning, according to Apple.

If running Leopard on a PowerPC, the external drive must be partitioned in the Apple Partition Map scheme; those running Intel-based Macs should use GUID partition scheme. Use Disk Utility to reformat the drives and then select it again in Time Machine.

Another problem encountered is not being able to see the backup volume. The problem lies, according again to Apple, is in using non-alphanumeric characters in the computer's name. Others say even after renaming the computer the problem still persists.

Update:
The Mac Observer pointed out that Apple has support documents for the issues relating to stalled or interrupted backups and for the invisible backups.

The "Mac OS X 10.5: Time Machine stops backing up to external disk" document deals with the issue that "after about 10 GB or more of data is backed up to an external disk, Time Machine may stop backing up."

In the meantime, "Mac OS X 10.5: Time Machine backups are not visible" deals with a problem in Time Machine "time travel" window where "past backups may not appear if your computer name includes certain characters."