Rem Dsktp Disabled after logon scrn en

Remote Desktop Disabled After Logon Scr
I am running 2 W XP Pro machines and connecting them with TZO and Remote Desktop. The connection is workinfg fine. The problem is that the client machine that the remote machine connects has the log on screen popping up and asking for the users passwords again. The machine is running and the user is logged on and I connect to it from the remote machine using the same log on. When I went to log in with remote it would not let me anfd said it was not available. I went to the client site and saw the log on screen. I have set up a dummy email account to check for email every 5 minutes and think this will solve it. Any better ideas?