Can you ever have too much antivirus?

Sadly today I found out you could. When closing Visual Source Safe 2005 my computer blue screened with the error:

NO_MORE_IRP_STACK_LOCATIONS

Apparently this was caused because I’d installed multiple anti-viruses to ensure protection against a nasty little worm and I’d forgotten to clear them off once I was done.

The solution was simply to delete the unwanted anti-virus but Microsoft do have a hot fix too if you find your self in the same situation but wish to keep your anti-virus: http://support.microsoft.com/kb/906866