I have a dsm-320 and have had no problem using the windows media player "plays to" feature to control the DSM-320 from my laptop. I right-click on a song, scrool to "plays to," select the DSM-320, and the song begins to play through the DSM-320. I really need this feature because I sometimes use the dsm on home stereo systems that don't have a TV nearby, so no TV screen to control the dsm from.
I bought the 510 because the 320 does not support WPA wireless security. I figured it would work with WMP 12 "plays to" the same way as the 320. However, even though I get a "plays to" in the WMP menu when I right click on a song, and WMP sees the DSM-510 as a device to play to, it doesn't play the song and ultimately gives a message that it can't connect to the DSM-510. Any idea what the problem could be? I have tried disabling firewall, AV, etc., even though the dsm-320 works fine with the firewall and AV enabled, but no success...