Had some strange stuffs happening with my ubuntu install (been upgrading and no reload since 10.04, was using a 32bit machine before that, replaced the hard drive once, motherboard once and various other things inbetween so the install was getting a little dodgy).
I started having it halt on boot and decided it's time for a fresh install.
Live cd in, mounted my encrypted home folder (bout 10 minutes), copied all my stuff to another drive (few hours, about 600GB), fresh install and copied whatever I needed from the old home folder into the new one.
Working perfectly, including all my settings for firefox, virtualbox etc.
nice and simple