just tested the siig JU-H20211-S1... still no protected playback.

this was recommended by them to support hdcp. it looks and seems to be the exact same device as the diamond dv100.
again. called support. again finger pointed back here.
same story. unplug, replug, uninstall, cleanup, reinstall, replug, "oh maybe its defective because it should work. maybe try contacting displaylink"
here's the list of (3x chipset) devices which i've tried to date:
diamond dv100
hp 3005pr
siig CE-H20W12-S1
siig JU-H20211-S1
pretty much hit a dead end here, and going back to a vga cable.
if it makes you feel better the trigger products while differently partially working aren't functional either (and are much slower and laggy).
all this because amazon switched to silverlight. ugh.
good luck with driver development.