"Unable to complete backup. An error occurred while copying files to the backup volume."
According to Apple, the problem stems form the hard drive’s Master Boot Record (MBR) partition type. In order to get past the error message, users need to completely clean up the external disk so that it would be supported by Time Machine. Users with PowerPC-based Mac are instructed to run the "Apple Partition Map" partition scheme, while Intel-based Mac owners are to use the "GUID" partition scheme.
The other hot software issue burning on Apple’s forum is that users are sometimes unable to see their backups, although Time Machine has successfully completed the operation. According to Apple, the problem is only “available” on computers with non-alphanumeric character in their names. Also, the company adds, “If this is a new Mac, make sure the computer name uses the same as what was used on your previous Mac.”
Various other malfunctions have been reported to plague Time Machine, such as corrupting drives or not being able to finish a backup. Numerous comments have been posted on the matter, but here’s one that deserves a piece of (apple) pie. User DoTcOmNaMe wrote:
“i wish time machine could take me back to before i upgraded and tell me not to buy leopard!”