Okay Andy .... it's starting to sound like a corrupt cookie ... but just to make sure we're on the same page:
1. Are you running a version of Windows - if so what version? Win ME has some problems and does strange things.
2. Are you using Internet Explorer or some other web browser?
If you're running under Windoze and using IE for a web browser .. try this: After you log in .... click the "log out" button, click on "yes" you want to log out and then click on the "return to the page you were viewing" (or words to that effect) link. This might reset the bit in the cookie that handles loged in/out status. Then, log in again - remember to make sure the "remember me" box is checked. Once that is done ... close your web browser. Now, open it again and log onto www.discusscooking.com
and you "should" be logged in.
Let me know if that doesn't work and I'll tell you how to physically remove the DC cookies and start over from scratch.