"I also changed my home page setting in IE to just www.thechipboard.com."
You have to set it like that.
Last visit time is set at 30 minutes AFTER you open the site for the very first time you set the cookie. Thats how cookies work.

I presume you have saved your preferences?
Try saving them again, quit the site and IE, and dont open it again for 31 minutes.
The click 'mark all messages read' and it should start over.