Is there any way to change the way control points are set up? I'm porting my remake of dod_cherbourg, not for the contest but any potential map ideas I have might run into the same problem. I'm using liberation mode, and the default cap time (feels around about 30 seconds) is far too long for some of the points, and there's also no way I can find of forcing a minimum number of players for an objective.
It does this when you open the model viewer while the current window is in maximised mode. Resize to the 4-window view and it should work. Sometimes it will still do it the first time you try to open it again, just close the model viewer and re-open it. It's a really annoying bug but that's definitely the cause.