AAAAAAGGGGGHHHHHH!

Recognize that? It's the magic word employed by average linuxbox users who upgrade Ubuntu Hardy Heron to Ubuntu Intrepid Ibex to Ubuntu Jaunty Jackalope in a single span of 20 hours.

There are a number of things that go wrong. There are a number of things that look right. Which is which? It's 3 a.m. Sleep is required...