I've installed several of these workstations and they are an excellent option for our employees. The problem I am having is with the monitor arm tension. The employee complains that he can not raise the monitors, they just flop back to the lowered position. Is there a tension adjustment on this unit that I am missing? I know of the one at the top of the column for the entire station, but can't find the one for the monitor support bar. Any help would be greatly appreciated!!