Terminal Services

I am Running Windows 2000 Server with Terminal Services using Citrix
MetaFrame 1.8 and would like to automaticaly log all sessions off on a
specific day and time. I tried writting a batch file with the
logoff.exe file in it. If i run the batch from from the session it
logs the session off without any problems, but if i add it to the
Scheduled Task list it runs but does not log the session off.
Can any one steer me in the correct direction?

P.S. I tried the Microsoft Knowledge Base Article - 259436
         How to Log Off all Terminal Server Session Users from a
Command Prompt. The article says it is for NT 4.0 it did build the
text file like it said it would however it did not perform the logoff.

Any help would be great

Thank you
Ian