timeupdate.exe...help much appreciated!

Hello all,

Sorry to bother you, but I seem to have a rather bad problem with my computers...

We have a few PCs here (all XP) and a lot of them started displaying porn popups on Friday. Well, someone here ran ad-aware and spybot and this seemed to stop them.
Now all these PCs have a process called timeupdate.exe running, and an entry in the registry (in Local->MS->Windows->CurrentVersion->Run) with name: Windows Registry Scan and Data: timeupdate.exe (Housecall, Ad-Aware and Spybot don't pick this up). I stopped the process and deleted the reg entry but it seems to keep re-appearing.

Now, though, many of the people whose PCs had this are now reporting that their Word documents keep getting corrupted...seems rather worrying.
I googled timeupdate.exe and the only virus I could see related to this is the 'Vote' worm...(W32.Vote.B@mm) but I could find none of the files on my PCs that this worm is supposed to create and none of the other symptoms that are listed. (this thing seems to have been writen for ME/98, so maybe it's ineffectual on XP?)

What I'm wondering is: Have I cleaned everything up OK? Is this timeupdate.exe thing harmless? Or should I pursue it?

Many thanks for any suggestions.

Kovich