The viewer does not seem to work well under any circumstances and should be seen as a 'stop-gap' solution.
The iOS Player is great, I finally got it working last night and I'm loving it. The issue I had was that it would run but wouldn't detect the broadcast, it turned out that it was because I had Bluetooth turned on. The Viewer worked fine with bluetooth running on my iPod touch (4G) but the Player didn't.
Here is the advice that got me through:
"If you go to your network adapters page, is there more than one currently active? Some people have VMWare adapters that interfere with the broadcast. Try disabling all but the one that connects you to the device and seeing if that works."