php session variables limited to 1 character -- please help

Hi! I've got a very strange issue that is basically cutting off session variable data after 1 character. When I set the session variable as "50" it comes back as "5". When I set it to "XYZ" it comes back as "X". I have a script that is taking $_GET['State'] variable and setting it to a session variable named $USER['State']. This worked fine until a few days ago, but now it's persistent! Any ideas what might be causing this?? I've searched the web/lists and can't find any reference. http://www.triptrivia.com/step2-debug.php?State=abc Thanks, Zac