(RADIATOR) Deleting Rogue Sessions Automatically..... Help!

[Brad Green - Fox All Services P/L]

Hi guys,   Im running Radiator and am having trouble with a few things. My main issue is that some sessions are kept alive when the user has long since disconnected from the service. Is there a modification or a line I can put in to stop this from occuring? Im just wanting to put in a line that basically tells it to delete a session if it cannot communicate with it (but it cannot be by IP address, as the IP addresses are dynamically assigned to users, so the same IP could be in use but for a different user)   Brad