I was just playing with the affiliates page and entering different email addresses to see the affiliate ID change. I was using Internet Explorer 7.0 (haven't upgraded to 8.0 yet).
The cookie was somehow stuck. It wouldn't change no matter what I entered. I was puzzled because the code is pretty straightforward and I had never seen this before.
I finally cleared cookies and it started to work. I could enter different email addresses over an over on this page and the cookie would be set properly.
I Googled "stuck cookies" to see if I could find anything about an Internet Explorer bug or a PHP technique I needed to know about to avoid stuck cookies. I couldn't find anything.
Anyone ever run into this? What's the solution (other than clearing cookies)? I need a solution to unsticking a stuck cookie programatically in PHP without resorting to asking the user to clear their cookies.