I don't know if this is the right place for a bug report, too.
I used Dazzle during a presentation yesterday. It was on a Powerbook G4 12" with the presentation running on the beamer, while having the presenter screen on the Powerbook's display.
I used the Scribble plug-in to cross out some things on a slide.
It was a bit weird moving the (OmniDazzle) mouse pointer over to the second screen, but it worked. I also could draw the lines on the second screen.
But when I attempted to clear what I had drawn, nothing happened. I guess, OmniDazzle tried to clear the first (main) screen and wasn't aware of the second. Unfortunately, the consequence was, that I couldn't advance to the next keynote slide anymore after that.
The fortunate part was that it was my second last slide, and the last one wasn't so important. But I guess this is a bug that could be very annoying for certain users.
p.s. There was something funny happening after that, too: I have talked about v. Hayek's opinion on social justice (He doesn't like it very much). That was the reason I crossed out everything he didn't like about it. As this was my last slide, I kept it up when we discussed the topic. Some time later, someone made a good point rejecting v. Hayek's position and, as I was using the trial version, OmniDazzle quit after an hour, and the lines disappeared, revealing again what I crossed out before. It was a good laugh. When Dazzle quit, I could eventually even show my last slide. :)