sessions garbadge

Hi, My gc_maxlifetime = 3600 (1 hour) and my probability = 100 , just for testing . When i create a session on my site and i dont log out , the session var will still remain on the server , ok , after an hour (not exactly an hour) , when i surf the site , the collector destroys that var on the server (linux server) ! That is how it should work ! But when i create a session at say 23:36 , the session var will still be on the server at 8:16 (after the carbadge collector came around) , why does this happen , does php work in a 12 cicle only , or what is wrong ? Thanks Shaun -- Novtel Consulting Tel: +27 21 9822373 Fax: +27 21 9815846 Please visit our website: www.novtel.co.za