OK my subtitle issue is not related to the mysql database.
It is related to SMB.
If I have the subtitle file in the same directory as the movie on an SMB source - CRASH
If I have the subtitle file in the same directory as the movie on an NFS source - WORKS
If I have the subtitle file in the same directory as the movie on an LOCAL source - WORKS
So I guess I can work around this by having a custom dir located on an NFS (or LOCAL) share for the subtitles (I've never tried this before, but I think I've seen settings for this)? I'll try it out later this week.
Odd that the movie is fine over SMB, it is just the subtitle files that cause problems.
Anyway, if anybody has any ideas as to why subtitles over SMB causes crashes - I'm all ears.