The default timeout for a session is 20 minutes.
You can change it in ASP by doing
session.timeout = 10
Then, the session will be destroy after 10 min and it will free up a license.
You can also use this to release a license when a report had been view
set session("oPageEngine"

= nothing
set session("oRpt"

= nothing
set session("oApp"

= nothing
Session.Contents.Remove("oPageEngine"

Session.Contents.Remove("oRpt"

Session.Contents.Remove("oApp"
If you want to see more sample code, go to Crystal decisions web site at
to download the file aspxmps85.exe
This is if you're using ASP and RDC to view your reports,if you're using VB, then maybe someone else will be able to help you more since i only use ASP.
HTH,
Martin