Remote desktop connection error

[misterb]

I have the following problem and can not solved it...

I use the remote desktop connection since years on my server 2000 machine.
Recently we changed the organization of the system from workgroup to domain. I add then 2 servers to manage the domain, they are server 2003. I upgrade then the server from 2000 to 2003.

Since then I cannot connect to the initial server. The connection begins (so this is not a firewall blocking the port) but it is closed directly by the remote host with the sentence:

connection closed by the remote host.

I already figured out some issues regarding the presence of users with blank password and some strange settings in the registry..

But the problem is still there...

Thx for help