It's odd, but a friend of mine was telling me she had this problem the other day. Now the same thing is happening to me ):
Procaster seems to be working on this end (and I can see footage from the preview) but my viewers claim to all see a black screen. I even tried capturing the livestream page itself, but all I could see on the video was a black screen, and an occasional flicker of 'offline'.
Also, since my first stream I've done various tests, but they don't show up under recent videos. They're listed in my studio though...