I have problems with rdp on a very random basis. You're best bet is to get a third party remote control program.
Currently, at work, we are using Remote Control Pro by Alchemy-Lab. But I'm trying to get the manager to buy CrossTec Remote Control because it has almost zero limitations. But, you probably don't have the extra $400 to spend on it for 3 computers. (We're buying 50 licenses for $3700!)
Look on sourceforge.net for remote control programs. They've got a few good ones and they will probably work better than microsoft stuff. Search for vnc.