Rondele,
I don't think it is necessarily the browser itself that is the problem, but perhaps a setting within the browser...  It sounds like the cookie is either getting cleared or not getting created.  First, make sure you have cookies enabled.  The following link is a good reference for these settings on different browsers:
http://www.google.com/cookies.htmlIf they are enabled, look for something that may be clearing the cookie.  Sometimes "cleaner" software or some security software will remove cookies.  I know that Spybot Search & Destroy is one that will clean up cookies.  I am assuming you are logging in for "Keeps" when you login to the Conversation Board.  I hope some of these ideas help.
Allan