Loosing $_SESSION vars somewhere...

Hello everyone! I'm running PHP v4.3.3 on an Apache server. I'm using $_SESSIONS to track student information while they're in a course. Every once in a while some of the session vars suddenly go blank! What disappears is the information gathered and stored from the login - so it's the "oldest" data gathered. At first I thought it was session.cache_expire so we expanded that from the default 180 to 600 minutes - but the problem remains. What I've done at this point is to implement a new function that repeatedly checks the value of certain $_SESSION values on each page. If a value suddenly disappears then I pop an error to the user and write the event to a text file on the server. This is okay as a stop-gap, but I need to track down what's causing the problem in the first place. Any ideas? tia Mark H -- Mark Henry Enterprises, Inc. Phone/Fax: (704)721-6685 mark@markhenryenterprises.com http://www.markhenryenterprises.com