Comment 31 for bug 542660

(In reply to comment #8)
> Created an attachment (id=35659) [details]
> Xorg.0.log when the patch is in use
>
> I'm still having this problem using kernel version 2.6.33.3-85.fc13.x86_64 on
> my iMac 27" / HD 4850. This kernel supposedly has the patch from Comment 6 in
> it.
>
> When using the default radeon driver, the screen turns black as soon as X
> starts. (I'm not having these problems when using the vesa and fglrx drivers.)
>
> Attached is my xorg log as it was a few seconds after the screen turning blank.

According to your log this log you are not using kms. Looks like you are seeing bug 28267.