Need help with PHP log-out/session issue

I'm using the PHPmotion script, with a use-a-credit to view a video mod. When the user logs out, the viewed video should not be available again to view, until he logs back in and chooses it, via a credit, but it is still available when he logs back in. Any ideas on what file may be responsible for what I guess you could call 'clearing the session'?
Any guidance will move me towards a remedy, thanks

 

You're probably better off asking here: http://phpmotion.com/forum/