I finally found out how to fix my problem playing OGM files with multiple streams under BSPlayer.
I had to go into the properties (of OGM) to disable the setting that's called something like "Enable all streams during playback."
Why is this the default? Each time I reinstall the K-lite codec packs (like when I upgrade) it gets enabled again.
Anyway, I just wanted to bring it up because I think lots of others had this problem. I now know how to manually change the setting so that's what I'll keep doing if there is a good reason to have that default the way it is currently.