rtsp:// stream doesn't show correctly?

[groovykool]

When I try to play a stream from a dahua ip camera with a URL like this:
rtsp://user:[email protected]:portnumber
the stream "plays" but is all black? I get no error messages or exceptions? Maybe it isn't playing?
The camera stream works fine from ffplay and VLC.
fmpeg supports this url form.

Any idea how to debug this? Since it works in ffplay I would lean towards a bug in MediaElement? Or something I'm missing?