Termial Services session to session conection

Here is the issue in point form

- two Windows 2000 application mode Terminal Servers in a Windows 2000 environment
- each server provides various applications and desktops to users
- each server is independent (no load balancing or cluster)
- users can log on to each server as always using credentials as always
- From time to time users logged onto a Remote Desktop session require an application on the other TS.
- As of last Friday a user is no longer able to do this, when a user attempts to access the application mode TS this message
The client could not establish a connection to the remote computer
The most likely causes for this error are:
1) Remote connections might not be enabled at the remote computer
2) the maximum number of connections was exceeded at the remote computer
3) a network error occurred while establishing the connection

- the user can access a Remote administration mode TS from the TS session
- if the user is added to the power users group on the TS that is trying to access the other application mode TS the connection is allowed
- if a user logs onto a windows 2000 or XP desktop they can gain access to either TS
- if a user is given access to a Remote administration mode TS and attempts a connection to either Application mode TS the connection is successful

The bottom line is: a connection from one application mode session to another is denied for a regular user.