The only way I have found to download from sites like japanhub, etc using JWPlayer, is to utilize quicktime. The problem is you have to download in real time and its quite laborious. You play the selected movie,launch quicktime player and select new screen recording, click on the record button and you can either record the whole screen or just drag your mouse over the screen playback area. In addition, at least on a Mac, you have to download the Soundflower audio application which allows you to record audio while in the screen capture mode, and select Soundflower 2ch. As I said, it is quite time consuming and a real pain. Once recorded, you quite quicktime and save to a desired location. The real drawback besided the realtime recording is you also capture those annoying video ads that are on each page of those sites. The only benefit is that you can find some hard to get titles that are nowhere else on the web except for R18.com.
Larecjv I will try your method, but I don't think it will work for me, but worth a try. I have had the same problem that
bluearp has had. If anyone else, can add, I would appreciate it as I said there are some very hard to find titles on these JWPlayer sites.