Description of problem:
As an experiment I've update xorg, mesa, libdrm and libpciaccess on my i386 F-8
intel integrated graphics machine to the current xorg-x11-server 1.4.99 and
related versions in rawhide.

After this switching back to a text-console from X no longer works, I get a
black screen and my monitor displays: "no signal" switching back to X again does
work.

I'm pretty sure you will need lots more info, please tell me what and I'll add
it here, maybe we need a howto file Xorg bugs wiki page?