Comment 8 for bug 719446

Hi Alan,
  Installing development versions in another partition is a good bet - however being a development version any type of hideous error might occur and destroy the other installation - that's what you get with development.

http://kernel.ubuntu.com/~kernel-ppa/mainline/daily/current/ would probably be the right thing to try for the upstream; if you install that you should still be able to boot back to the old one.

Dave