XO: LiveCD from today doesn't work

[Jon Stanley]

In order to have my XO look good for a photo that I was going to put
on Amazon, I spun a new LiveCD  from today's rawhide. When booted on
the XO, it gets to GDM, I select automatic login and click login.
Then X crashes, and I'm back to GDM.

I'm not really a desktop guy to even know where to begin looking at
this.  OTOH, the rawhide machine that I used to spin the LiveCD, I
just updated it and everything works fine, so this is probably
hardware-specific :/