My Book Live not appearing as a backup target

I am having the same problem on one PC (a WinXP machine). Was working fine for weeks, and then the target seems to have disappeared about the same time as Quick View 2.2.  Have tried uninstalling Smartware and QuickView and reinstalling. Worked for about 5 minutes, then lost the connection. The MyBook Duo is seen just fine in network drives, and I have a timed batch file to back up the critical files on this PC to a fixed share (using XCopy), but would like to have the auto backup working again.

Help