Remote Desktop Disconnected

Hi there

One of my guys gets this error:

"The client could not connect to the remote computer.

Remote connections might not be enabled or the computer might be too
busy to accept new connections.
It is also possible that network problems are preventing your connection.

Please try connecting again later. If the problem continues to occur,
contact your administrator."

.... everyone else can connect fine, and he has erratic success with
connecting!

Any idea what might be the problem? We have enough connections open, and
we're running a 15-device license on W2k3 Terminal Server.

Thanks
Bryan