When was the last time you set your preferences? You may need to do that.
Also, there is a chance that your cookie has become corrupted. Try reseting your preferences, leaving the site, and coming back.
If that fails to work, you may need to delete your entire cookies.txt file, shut down your browser, and do a search for cookies on your hard disk. If you find it saved in your temporary files, delete it there as well, shut down your computer, reboot, and try again.
I know, it sounds like a big pain in the ass, but I've found in the past that sometimes this is the only way to fix the really persistant problems with the cookies that just won't go away.
Spark
------------------
Kevin Jon Schlossberg
SysOp and Administrator for BladeForums.com
Insert witty quip here