Nonstop backup ignores logical drive

True Image 2013 on Windows XPSP3:

I am trying to run nonstop backup on a logical drive (lettered) and a folder on the primary drive. Only the folder on the primary is backed up, the logical drive is ignored. The backup is to a network drive. I have tried using ASZ as the destination but get the same result.

If I attempt to backup only the logical drive I receive this error:
The backup location has not been found.
Event code: 0x00640293+0x00E4003A+0x00E4003A+0x00E4003A

I am able to make normal TIB backups of the partition to the same destination.

I'm having this problem on one computer. Others on the same network (same OS), using the same destination do not exhibit this problem. I have tried reinstalling True Image.