FYI: both Mint 12 and Ubuntu 12.04 use the 3.3.4 kernel, and Ubuntu boots, while Mint doesn't
You see, right there is where your mistake is
Ubuntu is in version 12.04 as you say, but Mint is based on the 11.10
version and, thus, has an older kernel (3.0012, I believe; forums say 3.0 but that's just unspecific). Linux Mint 13 (code-named "Maya") is soon to be released (just a few weeks more) and it *will* be based on Ubuntu 12.04 (thus, having the 3.34 kernel). Wait for that one and you will have no problem at all
Cheer up! Things are getting worse at a slower rate.