Touch&Go,
Had the same problem here in the office, solution to this is to do the following :-
Start > Settings > Control Panel > Administrative Tools > Component Services.
Click Services (Local) and scroll down for Messenger. Right click properties, then on the General tab :
Ensure Startup is set to Manual, then click Stop and Ok.
Has worked for me using Win 2000, maybe different procedure for XP.
Mat..
(PS - That job didn't happen in the end)