RDP - Login Problem - Access Is Denied

Hi,

I am suddenly getting an error when trying to logion to a WIN2K3 server with

RDP authenticating from a domain. The error I get is:

"the system cannot log you on due to the following error. Access is denied"

Sometimes after multiple tries I can login. On google searches I'm seeing

hints towards DNS and active directory. For testing, I created a temporary

local logon on the server in question and can access via RDP with this logon

no problem. Can anyone shed any light on this for me please?

Thanks in Advance,

Aidan..