some program got started in VNC session instead of local session

Dear experts,

(I don't know the exact term for the x session running at ctrl+alt+F7,
I just use "local" session here)

I am using RHEL 4.0 and configured a VNC service to be started at boot
time.

It seemed to be evolution email client's notification program got
started in the KDE session started by VNC. The result is every
notification is displayed in that VNC session. And every time I logon
the local session, I will receive an error reported by evolution
complaining it is started incorrectly (started twice I guess)

Could anyone help me with this situation?

Thanks!

Leo