Strange issue going on here. I have a new Windows 2008 R2 Server. I setup Remote Desktop on it. I also installed VNC. When I try to use either one from my Windows XP machine, I cant get it.
If I log into my Domain Controller and try it, it doesnt work at first, but if you keep trying it will allow you to login. Once I log out, I can then go to my machine and VNC or Remote Dektop in!!! However, if I logout and wait a few minutes I cant log back into the remote pc from my machine, unless I first go to my Domain Controller and login again, and then back to my machine again..