Hello,

I'm seeing something wrong with ati driver in Xfree 4.5.0, as well. 
XFree86 crashes with a SIGBUS when trying to probe the pci bus. Last 
line from XFree86.0.log:

(II) PCI: Probing config type using method 1

Last lines from XFree86 stdout/stderr:

(++) Using config file: "/etc/X11/XF86config".
Bus error (core dumped)

kdump says:

    859 XFree86  GIO   fd 0 wrote 45 bytes
        "(II) PCI: Probing config type using method 1
        "
    859 XFree86  RET   write 45/0x2d
    859 XFree86  PSIG  SIGBUS SIG_DFL
    859 XFree86  NAMI  "XFree86.core"

Sadly, I don't think I have enough time to compile -g XFree86 and to 
investigate further.

My video card is ATI Radeon X600 and my arch is amd64.

-- 
Mihai