Debian Installation :: Radeon HD 4670 - Display Completely Dark In X

I want to get Debian stable working on an iMac 11,2 (previous model):

1/ Same problem as this one, but I solved it by installing the fglrx-driver
2/ New problem: magic mouse and wireless keyboard don't work - solution: install .38-kernel from backports
3/ New problem: fglrx for .38 requires linux-headers.38 requires linux-kbuild.38...

So again stuck with the vesa-driver. I'm quite happy with the wireless mouse and keyboard working, so I'd rather stay with linux-image.38.

Two possibilities:
1/ I get the radeon-driver working
2/ I get the fglrx-driver working

I'd prefer the first method, but as you can see in the log (infra), there's a version mismatch between the kernel and the radeon-module. Any ideas how to get around this?

Using the radeon-driver gives me the following EE's in xorg.0.log.old:
(EE) RADEON(0): [dri] RADEONDRIGetVersion failed because of a version mismatch.
(EE) RADEON(0): Acceleration initialization failed
(EE) RADEON(0): clock recovery failed
(EE) RADEON(0): channel eq failed
(EE) GLX error: Can not get required symbols.

The las error is also shown as the only error when I use the VESA-driver; so clearly that is not the problem. I have tried without an xorg.conf, and the following xorg.conf won't work either:
Section "Module"
Load "glx"
Load "dri"
EndSection .....
I also tried the radeonhd-driver, but that doesn't change anything.