Yeah, player support for overlapping/adjacent subtitles is pretty spotty. On my end, the way I work around it is to not have them. I’m sorry to say that may need to be your solution as well, if MPC-HC playback is not an option.
Well, I also have a Popcorn Hour (I think it handles overlapping subtitles OK but haven’t checked recently), but for some reason it has a slight delay in displaying subtitles from BDMV folder structures. Building a media center PC (with perfect 23.976 playback) might be an option, but I don’t really want to go to the trouble right now. I’d like to get a new media player that handle all kinds of subtitles like a PC, not sure if such a media player exists but as to not clutter up your thread further, I made a request for suggestions here:
http://originaltrilogy.com/topic/Media-player-recommendations/id/56098