Today our noble and long suffering sysadmin took a look at my privilege settings.
The one local and two network admin accounts on the Dell had been switched to Debugger User. Apparently, it's going around the office.
As of 11/09/07 a search on Microsoft's site doesn't turn up any useful explanation. The current theory is that it's a .NET bug.
The way the security privileges had been reconfigured should, in theory, work. It's not, however, standard.
Anything that's not standard in XP is in the danger zone - and it's getting worse. My best guess is that Microsoft has stopped seriously debugging XP, and every security update and/or installation of new Microsoft software drives XP closer to entropic collapse.
Vista SP 1, not coincidentally, is starting to look better.
I am tempted to buy a MacBook Pro for the office and run Outlook and Access in an XP VM. I could use OS X for all my other tools, and if the system started misbehaving I'd delete the VM and restore from backup...