4 pointsToday's update to CA Auto Update will automatically apply the fix for this issue on affected systems (Whether or not the plugin is even enabled). You will though have to check for updates manually once to clear out the old update available status. If you are running @ljm42's patch script, you can safely remove it, as the Auto Update will not install the patch once 6.8+ is released.
1 pointI 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.