A little more data, when I use the guide and select 'stream anywhere' (instead of 'stream at home') the list of channels gets filtered down to about 3. I can pick one and the Flash player comes up, goes through the 'loading' and 'authorizing' stages and then I get the 'video streaming 1100' error.
So now I'm thinking it's some combination of windows 7 32-bit, Internet Explorer 10 and D* player 2.4.3 and Adobe Flash 11.9.900.117 that is really the problem since it's not windows firewall (the ndspcshowserver program was already allowed through but I have the same problem with windows firewall turned off completely).
Although I'd still like to know what D* thinks my 'home' network is, since my phone and other laptop can connect over either SSID with no problem.