can't boot with kms with my x700 rv410 radeon

[Dennis New]

I'm currently running 3.9.0, and the bootup process hangs/locks my
machine before the init stage is reached, unless I specify
radeon.modeset=0. But modesetting /does/ work if I load the radeon
module with modeset=1 after the kernel loads. So what could be going
wrong during the kernel loading?

The last things printed on the screen are either
  radeon 0000:01:00.0: radeon: using MSI.
or
  [drm] Driver supports precise vblank timestamp query.
  (if I disable msi)

I think the next thing that /should/ get printed is:
  [drm] radeon: irq initialized. (?)

Here's what dmesg says when I reload the radeon module with KMS:
  http://dennisn.dyndns.org/guest/pubstuff/dmesg-radeon-kms-module.log