SSO - logon session exists in R/3 even after EP logoff

Dear EP friends,

I am facing a strange and serious problem.

I am doing RFC invocation and displaying some reports on EP screen.

I have some 5 EP users, where all are mapped to a single R/3 user.

My problem is, even after EP user logoff, the R/3 connection session exists in R/3. It is not getting logoff.

This problem is really making overload on R/3 server, and making a queue of logon sessions.

Is anybody faced this sort of problem?

Please any body help me on this.

Thanx in advacen.

Early reply apprciated

kantha