correct me if i am wrong
You're wrong :-) That is exactly what doesn't work because one app's session can't be accessed from another app.
As I understand the problem, it's also the opposite of what is desired - not invalidating one session from the other, but making sure that they stay active. You might want to consider a shared data store for the session data, maybe a database.
[ September 12, 2008: Message edited by: Ulf Dittmer ]