I had the same prob. I bought a straight pin to pin RS-422 but did not work. Deklink SDI says no comm. I then rewired the cable with cross wires (2>8 and vise versa) and it worked. Thanks to this thread.
My equipment are:
DVW-M200P DigiBeta
Deklink SDI
Windows Core2duo Quad 2.4Ghz with 4GB Ram and 2T RAID0 Samsung HDD