You were correct in that you would want to go to Tools->Options->Media Network and ensure that "Use Media Network to Share this library and enable DLNA" is checked. This was working for me in .103 and I tried it today again and JRemote did not work. Oddly the above was unchecked on my system, checking it resolved the issue.
Not sure how it became unchecked as I don't think I knowingly did that. Such is life.