after u select the heading just right click with the mouse on top of the selector bug...this will not work with left click...there are some other things that will only work with right click, can't remember which ones but things like the IRS will turn clockwise with right click only and left with left click..so if left click does not work try the right click for that button or selector..also cycle view to 2d panel for a few seconds, that seems to free up some knobs...u can go back to 3d view after that and they should work. hope that helps