unauthorized guest login

I have a t41 IBM winxp sp2 fully updated with kaspersky (current ) spyware doctor scan spyware and have run F- secure black light all show clean no infections

The problem I seem to have is an irregular login on my guest acct that is disabled (about every week or so ). I login as admin ( my daily login ) and when I run belarc I see that my guest acct has been logged into, like last night at 12:02 am by guest ( the computer was on, but I was not on it at the time ) , the problem is my guest acct is disabled is this a problem or is this just a hiccup in win xp

I am stumped

Start | Run | Type compmgmt.msc /s, and click OK | In Computer Management expand System Tools--> Local Users and Groups--> Users, and check that the Guest account is truely disabled. This MSKB article may also be of some help to you...

How to Set Security in Windows XP Professional That Is Installed in a Workgroup
http://support.microsoft.com/?kbid=290403