I have almost the same problem. When I try to connect I get the little blue icon and every thing stops there. The server shows that the connection is there, but the local computer never fully connects, and the screen does not show up on the local machine. This is the 5th install for us and the other 4 worked perfect.
I did get this problem resolved. I had some problems when trying to do some updates to Windows 7 Pro on this one machine. Some files ended up getting corrupted. I did are-install of Windows 7 Pro (I didn't reformat the drive, just did a re-install). This fixed most of the problems, but still had the problem with Radmin. I then re-installed Radmin (didn't uninstall it, but just re-installed on top of the existing installation). This fixed the Radmin problem. Everything works good now.