Once you installed eTrust Agent on Windows Server 2003 be careful in session management.
Following scenarion takes place:
1. Administrator starts first terminal session to the box and sees the eTrust Realtime Monitor started normally.
2. Administrator disconnects (no logout!) the session.
3. Administrator starts another TS or performs logon on the console: Realtime Monitor doesn't start.
While eTrust runs in background and still protects the machine, there's no notification icon in systray neither possibility to start the updates manually, to open eTrust console etc.
Solution: logout all the connected sessions and restart eTrust Realtime Monitor manually ß it worked for me.