Broken Saucy update on a Zenbook

Confession: I did a somewhat rash Kubuntu Saucy upgrade while on holidays. It left me with a blank screen at startup. But what better entertainment can you have lying awake with a 6 hour jet lag at 4am than fixing your Linux?
The issue, by the way, is the Zenbook (UX31A) not liking the new kernel. The solution is Joseph Salisbury's inofficial kernel fix.