This is live right now, I am hoping someone can debug while it is.
The jump to live button seems to do nothing if you have rewinded. I have DVR set to 30 minutes and I can use the slider to move back but then can't use it to go forward as it fill out tp the current play time not the live time
You should be able to stop and start a stream on the encoder-side, or stop and start pulling a stream on the Wowza server-side, to a nDVR enabled application without problems. Make sure you are up to date with latest patch for your version of Wowza.