At every logon by any user, two blank error messages appear, one after the other. By "blank" I mean no text in either the message area or the title bar -- just the standard white-cross-on-red and an Okay button which has to be clicked to dismiss the box. No obvious effect on performance thereafter. I noticed this behaviour immediately after downloading and installing MSN Messenger 6.0. A recent download of Service Pack 4 may also be relevant. Nothing in Task Manager when the boxes are on screen, nothing gets written to the Event Viewer logs, no unexpected item in Startup or the registry's start list. What can this be? It's a real nuisance to keep seeing (and hearing) these pointless popups at the start of every session.

Okay ... I've seached my system carefully and found my own answer to this mystery. The empty error messages are generated by a prog called IGLXTRAY.exe in the folder C:\WINNT\SYSTEM32. That file shouldn't be there, because it's one of the items planted by the W32/Tzet worm. It must have sneaked in while I was downloading MSM Messenger 6.0 or SP4. I've disabled the worm and now I'm off to update my virus definitions ... BTW, I haven't seen these error messages documented anywhere as a symptom of Tzet worm.