I purchased OB+ in order to get a taskbar on my second monitor. I often switch from a docked (multiple monitor, external primary) to an undocked (one monitor) mode. When I undock, the bars from the external primary all move to the new primary (this is correct). The doc configured for the secondary monitor (which is now the primary) also stays, however (it shouldn't), and when I re-dock then all bars (both primary and secondary monitor bars) move to the new primary (external) monitor.