Let me explain... Really Alex hasn't sent me a patch...
I really like very much shadow dancer... Some user warning me about the issue on level 2.4 that was fixed on 147u4 so I fixed it.. I realised that had problems with save states also, so i began to dig and finally I have fixed the timers on 139 that were fixed by Alex time ago on 141u2.
Shadow dancer runs well now but other games from sega drivers keep broken save states because they really were fixed when Aaron did the work to modernise the sega 16 drivers on 146u5. Anyway caves ones works well now with Alex changes.
I stay there till I have time again to deal with the arm issues on newer mame builds and I try again to port a newer mame.
Yes I know you are not supporters from mame hacks like force 60hz. But this is a phone man and this option and hiscore saving are switcheable.. now shadow dancer runs like butter...