[jmh2002]

Im trying to recall (and I could be wrong), but I think a trick might be that you need to have System>Video>File Lists>Default Select Action set to: "Choose" in order to be presented with the option to "Resume" in the situation where you try to start playing the video again on another device?

Try it and see if it helps. Certainly on my previous mySQL setup it all worked for me, and yes I also confirm that you must stop the video in order for a resume point to be created.