Hi Adrian, we have that exact fluid head and love it. In fact I’ve had it for over ten years, and it’s been rock solid. So first of all, you got a very good fluid head there. But I’m not sure that I fully understand your question / issue. On ours, to move the camera forward and backwards on the head to adjust the balance, there is a red lever that you loosen, move (sometimes you have to wiggle it a bit, or tap it) the camera to where you need it to get the balance, and then tighten that red lever. Now when you say ” if I unscrew the front of the balance plate…” do you mean the screws that attach the wedge plate to the quick release plate? Usually two screws – a big and a small. One thing that could be happening is that one of these screws is somehow inhibiting things. They have to be the flat headed screws that came with the tripod and the wedge plate- otherwise they will block this motion. Make sense? Am I even getting your problem right here?
Tom Miller
Big Pictures Media
Denver, Colorado
https://www.BigPicturesMedia.com