Options reset when changing versions

I was using 1.6.2 to play in some servers, and 13w37b to test 1.7. While using the snapshot, I changed the music to 0%, the performance to Max FPS, and changed the sprint key to be tab. When I used 1.6 and came back to 13w37b all the options were reset. That also happened with my options in 1.6.

Steps to Reproduce:
1. Launch Minecraft, using 1.6 or 13w37b.
2. Change some options.
3. Change to another version and go back.