I noticed this issue today on an older development version of MediaFront, then I tested if it still was showing up in the latest dev and it definitely is.

If an user pauses the player when watching a RTMP live stream and then tries to resume the video, the stream freezes on the last frame shown. The debug output is as follows:

stream.pause()
Calling Flash Update: mediaPaused
stream.resume()
Calling Flash Update: mediaPlaying

This does not happen if a RTMP on-demand stream is paused. In this case the video resumes playing fine, giving the following debug output:

stream.pause()
Calling Flash Update: mediaPaused
Video: status = NetStream.Pause.Notify
Calling Flash Update: mediaPaused
stream.resume()
Calling Flash Update: mediaPlaying
Video: status = NetStream.Unpause.Notify
Video: status = NetStream.Play.Start
Calling Flash Update: mediaBuffering
Video: status = NetStream.Play.Start
Calling Flash Update: mediaBuffering
Video: status = NetStream.Buffer.Full
Calling Flash Update: mediaPlaying