Tim:
You might want to a "system-config-display --reconfig" now, to start configuring X from afresh. The updates *may* have resolved your previous graphics problem.
Bo Berglund:
But since Fedora won't start up how can I even do anything like what you suggest?
You'd start up in a text-only mode, which I thought I recalled you saying would work, then you'd run it. It'd probe the graphics system, and try to generate good settings, anew.
And if it starts up in a usable mode then I don't need it...
I thought you still hadn't resolved it?
With a prior release, or so, Fedora wouldn't start up graphically for a lot of people with a certain chipset, but was fine for others. The first X update to come along fixed that. I was wondering whether you might be so lucky, too.