For no particular reason I decided to run Belarc on one of my PCs. It showed a last logon of Guest on 11-01-07. I've never (knowingly) used the Guest account.
So I tried Belarc on my lappie, this time Belarc showed a last Guest logon of 20-1-07.
Any explanations? Is it possible that one of my apps somehow logs on as guest?
The only thing of possible significance I recall doing on the lappie on 20-1-07 was to delete an item from AVG's virus vault (sporder.dll, which had been sitting there since 30-10-06 due to a false positive in AVG picking up this file which is installed with Panda ActiveScan).