I did run into this situation at first, but thought I had it worked out in the posted fix(the trick was supplying both mime-types in preference order). I use one of the containers you mentioned as having the issue post-patch, but don't see the behavior here.
Did you edit the file manually, or did you use the script @ljm42 posted? If you edited it manually, would you mind pasting the exact line after the edit? It's very possible a typo in the right spot could cause this.