The scenario is this:
the just new docking station UD-3900 plugged via USB 3 to my DELL VOSTRO 3350, Intel i5-2410M @2.30GHz, 4GB ram, SSD Samsung EVO 850 with WIN 7 professional 64 bit and to
one Monitor HP 2311x @ 1920*1080 via HDMI and one Monitor Samsung syncMaster @ 1600x1200 via DVI port
Main screen HP, secondary Samsung, tertiary laptop screen (13" @ 1366*768).
No keybord, no mouse (using those of the laptop), no other device plugged, the ethernet is plugged directly to the laptop port.
When play a video file saved in the laptop, the video player shows the video properly only in the laptop screen.
In both the other two monitors I have this two behaviours that may occur with unknown cause:
A) the video player shows a still frame of the movie, no matter what is the resolution, while I can her the audio of the video and the counter of seconds goes on. When I keep the leftclick of the touchpad on the player window, it run smoothly perfect
B) the video player shows the movie with lower speed and with bad syncing of the image. In this case, a lower resolution file or a smaller window size of the player reduce the problem.
I installed the driver found at the addresse http://plugable.com/drivers/displaylink/