I don't know if Bsplayer can properly handle SMI subtitles.
Anyway, here are a few tips that help korean subtitles work on Mplayer (THE media player for Linux) :
- install korean language support
- read the subtitle file as unicode (typically, with "-unicode" somewhere in the command line)
Hope it helps.
The link to the related sources for Mplayer :
http://mplayerhq.hu/pipermail/mplaye...ay/001043.html