Can't turn off subtitles

On some .mkv files with multi-subs I can't turn off subtitles. I can browse through the different subs fine, but when I get around to "disabled" I still get one of the subs. These are not hardcoded subs. It doesn't happen with all files with subs.

The workaround I've figured is to create a blank text file with .srt extension, and point the subs to that file. But it would be better if this bug is fixed.