The first problem I see is that your rtsp stream repeats the domain twice. The poster.mov file also doesn't exist in the root directory of your domain, so you need a proper path for that.
Other than that, I'm not getting a plugin error with Safari on the Mac. Fix those two path issues and see what that gets you.
I just tried the rtsp stream with the proper path and it's acting like a Live Broadcast. I'm not very proficient with streaming servers, which is why I just gave up and hosted my movies as a standard file served via Apache, rather than encoding it for streaming.