[dfa0]

I know upgrades are supposed to work, but they almost never go 100% percent right.

Use dpkg/synaptic to backup your installed packages and backup your /home...then commit to the time to going fresh install. If you use LTS releases, you'll only be doing it at most every other year.

IMHO, it is worth the time.

[XorNot]

I've had very good luck lately simply adjusting my sources file and typing apt-get dist-upgrade lately - though this is using Mint as the base distro (which in turn uses Ubuntu too).