mcafee/service pack 2 security bug/glitch

I can usually post to these forums as a guest from a work's pc or whilst using the one in my local library. Each time I try to submitt a post using my dad's machine i get a screen come up with just "invalid session" written on it. I can only assume there must be some kind of conflict between the site and my dad's machine.

I guess the site's asking my dad's machine to do something and the MC is saying NO so therefore I cannot post my entry to the forum and get the "invalid session" notice.

I have tried it on a number of different forums on this site and get the same response each time..

same here butonly when im on my kneeboard

It may be his browser settings, a firewall, something that he has on his machine that won't allow this site.

AOL does that.