This problem happens when you are using Remote Desktop Connection Manager (RDCMan) with not updated Terminal Service Client.
To fix this problem you have to download and install the latest Terminal Service Client 6.1 from below website.
For Windows XP:
http://www.microsoft.com/download/en/details.aspx?id=7208
For Windows Server 2003:
gracias excelente tip me resolvio mi problema.