Ok let's get back to basics:
1) First let's rule out permissions issues: what happens if you try to run MC as root (or using sudo)? How about as a different user?
2) Second, let's rule out package issues: In your apt output in your last post it says "36 not upgraded" which means apt thinks you have 36 out of date packages. If you're using Mint's graphical package manager, you may be missing package updates. Mint filters out certain updates that it thinks might be disruptive, but that means that you'll be perpetually out of date on some packages. IME it's desirable to stay as up to date as possible, and the way to do that is to run sudo apt-get update && sudo apt-get dist-upgrade
That will update the database of available packages (the "update" part) and then upgrade all the packages to the latest versions if possible, while resolving any new dependencies that packages may have (the "dist-upgrade" part). If you haven't run "update" in a while, you may have many more out of date packages than 36, but apt just doesn't know it because the databases haven't been synced. If you haven't run dist-upgrade in a while, some of your packages may have new dependencies that are not currently met.
If you see errors while trying to upgrade packages, don't force it, report back with the errors and we can talk through it. It can be disruptive to upgrade all packages, but I've found that the cost in disruption of not upgrading typically exceeds the cost of upgrading over the long term, and I take a dim view of Mint's selective upgrade system.
3) Third, let's make sure we're all on the same page distro-wise: Are you running plain Mint Cinnamon 17, not Mint Debian Edition with Cinnamon? Or something else? Are you running a 64-bit or 32-bit installation? Are you comfortable enough with Linux to try a different desktop environment to see if it's Cinnamon related (if not, no worries).
4) Fourth, does other Linux A/V software work normally? What happens if you try to run banshee or clementine? How about VLC player?
I don't have a mint build currently so I'm a little limited, but I've used Mint 17 in the past and have a current Debian install (which is the package source for ubuntu and mint), so hopefully I can help keep the ball rolling.