Quote Originally Posted by mc4man View Post
Can't dupe your issue no matter how I try, all changes persist & are reflected in mimeapps.list
Have to go out, will give some thought
A user in the Ubuntu IRC channel was able to duplicate my findings. They said since GCC (gnome control center, aka system settings) does not hold the settings properly, but Nautilus does (Right click file - Properties - Open With - Set Default), that it's a GCC issue, so I filed a bug accordingly.

https://bugs.launchpad.net/ubuntu/+s...r/+bug/1177012

Basically it seems like the applications fight over who will be the actual default application. If SMPlayer is installed and I select it as default, it refuses to let me choose VLC or Totem. I mean, I can select it, it looks fine, but if I close/reopen it's back to SMPlayer. If I apt-get remove smplayer and do the same things, this time Totem is the one who's continually set as default even if I select VLC as default. But fortunately as least the Nautilus way (properties - open with) works without issue.