Subtitle problem (vobsub)

Hi!

I have a problem displaying subtitles in BSPlayer. I ripped them with vobsub (out of GKnot) an have a 32MB file with the .sub suffix. My movie plays back fine in BSplayer, even with dolby digital sound, but when I try to load the subtitle, nothing happens and the "show subtitles" option stays grayed out in the Subtitles... menu. What am I doing wrong? Is vobsub not supported?

Thanks, Frank