I have had this happen, just now, as a matter of fact. I am running my second copy on another computer on my network, RSOIP. BCD536HP. I have clicked hold and avoid sequentially on the remote copy. The transmitted audio continues, but the display freezes up and scanner button presses no longer seem to have any effect. It has happened a few times before. Trying different things, the solution ends up as: stop and start the serving RSOIP, then restart the client RSOIP. I haven't mentioned it before because I figured it was my fault for dropping instructional packets on top of each other.
Edit: After starting a copy of the ProScan Client on a third computer, to see if the server side was kronked, looking back at the copy on the original remote, all was again well. Duh, now I really don't know what just happened.