I'm running 32bit MC 23.084 on 64bit Win 7 Pro Sp1.
Yes, the Library Server has an Access Key but thats not used by DLNA clients.
Under Advanced, I have DLNA Server, Renderer and Controller checked.
I tested this several times with both of my servers, using Start Up options "Media Server only" and "Both MC and MS", each time with the windows service also set to auto-start. Then, with no DLNA servers showing up on the TV, I start the server cold and wait 5+ minutes. Within about 2 minutes, Windows Media Player shows up on the TV as an available DLNA input source. But the MC DLNA servers won't show up until I login to Windows on the server. Contrary to my initial post, I don't have to launch the MC console, I just have to login. So anyway...
That said, the DLNA feature is cool and works well on my TV but I won't be using it now that I've discovered the beauty of using Theatre view on an MC client PC that is connected directly to the TV with an HDMI cable (in dual monitor mode in my case). All I have to do is launch MC on the client, load my MC server library, snap the MC window onto the TV and launch Theatre view. Wow! This is just what I wanted in terms of full functionality and control over TV recording and playback "from the couch" (just like wmc/xbox, only better!). I even have the mce remote control working! Now for some custom views maybe...