Hmmm, just made a post but it didn't got here?!
Anyway, i upgraded to 6690 (64bit) or something like that, the version on the main site, subtitles didn't work. I choose mpv, windows 7 64 here. I uninstalled and installed 6719 from unstable. I reset the preferences too. Same thing, no subtitles. Oh, choosing mplayer instead of mpv, make the subs work again.