I have the Plugable UD-160-A USB 2.0 Universal Docking Station and am running an external monitor (among other things) off of a HP ProBook 4520s.
I received the docking station in December 2010 and it ran beautifully up until two weeks ago. Since then, the external monitor flickers on and off (several times each hour initially, but more and more frequently now), will lose its ethernet connection and all peripherals will cease to function. When it does work, the external display is PAINFULLY slow and fuzzy–dragging a window onto the external display will take 15-20 seconds to complete and resolve.
I have installed the newest DisplayLink driver and have all recommended and optional Windows 7 updates installed.