I had a problem with Shareport (1.14) not detecting my Seagate 1 TB USB HDD connected to my DIR-855 (1.12EU)
It would only detect if i connected my laptop (Vista) to the DIR-855 through cable, not wireless.
Problem was resolved after disabling my ethernet adapter, keeping only the wifi adapter enabled, then rebooting.
So it seems like Shareport “locks” onto the initial adapter used for connecting.
Now it works like a charm, with no noticeable delay r/w on the HDD vs connecting directly to the laptops usb-port.