I have one user that can log in, but as soon as he clicks on any of the forums it logs him back out. I have resent him his password a couple times, and he has clicked the link to delete his board cookies. Is there anything I can do on the database side? He does not want to clear his internet explore files because he has all his passwords saved for other sites , and this is the only site he is having issues with... IS there a way for him to tell which cookie is our sites cookie?

Thanks,
Ian

It sounds like a cross domain cookie issue, he's likely logging into:
yoursite.tld

Vs what you have set to the primary domain:
www.yoursite.tld

So when he clicks to do something it forwards him to the other domain