Problem with sessions expiring?

Hi I have a process for people to apply for awards online. The login is controlled using sessions, with a basic session variable set with the username of the person logged in. In PHP ini the session cookie lifetime is set to 0 - ie. until the browser session finishes. Manyof the applicants are using the system, and it is fine. But a significant minority are having the same problem. They log in, spend some time entering data into the fields on the form, and when the hit the button to either save or submit the entry they get a 'you are not logged in' message and - worse - lose the data they have so far inputted. One user experienced this after an hour and a half's work - but others have had problems after considerably shorter periods of time. As far as I can tell, the problem is not restricted to one platform, and I haven't yet been able to locate anything that applies to them that wouldn't apply to others who have successfully used the system. Is there any known problem - perhaps in relation to certain kinds of firewall - that would explain this behaviour? Any thoughts on the workaround I might do short term (above and beyond encouraging people to write their applications in Word before submitting them) that might alleviate the problem? Deadline for the award is two weeks and traffic is getting quite high. Any help you can give me before it gets worse would be gratefully received! Thanks - Mallen ________________________________________________________________________ This e-mail has been scanned for all viruses by Star Internet. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk ________________________________________________________________________