Wordperfect saving document with Hidden attribute enabled

I have a user with Wordperfect 12 that has an unusual issue occurring.  In case it matters, he is running Windows XP Pro (SP3) as a member of a domain (with a 2003 SBS server) and has his My Documents redirected to a network share on the server (and offline files enabled on the entire My Docs).  He's using a Dell Latitude D630 laptop.

Occasionally, when he goes to save his time sheet document, it saves OK but marks the saved file as hidden, so he doesn't see it.  In addition, it creates a non-hidden file named something like PFTA2D.tmp with a size of zero bytes.  When this happens, I go onto his PC, turn hidden files visible and open the file, then re-save it.  No further problems.  I turn hidden file visibility off (to limit future confusion).  However, I'd like to figure out what's causing the problem.  

Originally, I thought it might have been related to offline file sync <sarcasm>(since I know how wonderfully reliable it is) </sarcasm>, but he hasn't disconnected his laptop from the network at all this week, and it happened again on Monday (but not Tues or Wed).  So that may not be it.

This only happens with his Timesheet documents, never with client or court documents.  We've had it happen in more than one folder, including a blank new folder (but all within the same folder tree).  There are 20+ other users on the network, at least 11 of whom regularly use WP and at least 6 of whom have identical Timesheet documents in their own My Docs folders.  None of them are having this problem.

I'm going to start by re-installing WordPerfect, but since I can't figure out what's causing this, I'm not at all confident it will be resolved.