Windows Messenger 5.1 on Terminal Server

Hello;

A client only allows the use of Windows Messenger 5.1 at their site.
Recently, we upgraded this client to a new Windows Terminal server which they
use almost exclusively for their work.

On their old TS, Windows Messenger 5.1 would automatically log in (save
username and password) when they logged onto the TS. On the new TS, they must
log in to Windows Messenger every session. Since it used to work
automatically, they want it to work that way again on the new TS.

Since this does not happen to anyone with administrator permissions, I am
assuming it is a Terminal Server security setting that (dis)allows caching
the users password for Windows Messenger.

Does anyone know what I will need to change so that all users will be able
to save their Windows Messenger 5.1 passwords for their terminal server
profiles?

Thanks.