PHP Authentication Cookie Issue

Hello there,

I have written an app which uses php authentication. I had it working
fine on one system, but I had to move it to a dedicated webserver.
Now, I can only login if I clear my cookies. I can then login, until I
hit my logout button, which destroys the session, and then it won't
redirect to the correct page. The system I wrote it on was using php
4.3.9 and the server it is now on is using 4.3.2. Anyone know of major
differences between those versions that would do that? The answer is
probably obvious, I'm just not seeing it. Thanks in advance!

Derek