Comment 3 for bug 368187

No no no! This is not a duplicate of bug 346028! I am not using fglrx, I uninstalled and blacklisted it completely, and moreover, the problem happens by booting the jaunty cd installer, which loads the radeon driver by default. I am attaching the files that you asked. I also got these messages on dmesg, which might be related:
[166956.852166] mtrr: no MTRR for e0000000,10000000 found
[166958.278853] agpgart-intel 0000:00:00.0: AGP 3.0 bridge
[166958.278872] agpgart: Xorg tried to set rate=x12. Setting to AGP3 x8 mode.
[166958.278881] agpgart-intel 0000:00:00.0: putting AGP V3 device into 8x mode
[166958.278928] pci 0000:01:00.0: putting AGP V3 device into 8x mode
[166958.297434] [drm] Setting GART location based on new memory map
[166958.297440] [drm] Can't use AGP base @0xf8000000, won't fit
[166958.312326] [drm] Loading RV635 CP Microcode
[166958.312733] [drm] Loading RV635 PFP Microcode
[166958.327685] [drm] Resetting GPU
[166958.446006] [drm] writeback test failed 0 deadbeef
[167032.472527] [drm] Resetting GPU
[167032.568381] mtrr: MTRR 2 not used
[167034.046881] agpgart-intel 0000:00:00.0: AGP 3.0 bridge
[167034.046901] agpgart: Xorg tried to set rate=x12. Setting to AGP3 x8 mode.
[167034.046910] agpgart-intel 0000:00:00.0: putting AGP V3 device into 8x mode
[167034.046957] pci 0000:01:00.0: putting AGP V3 device into 8x mode
[167034.066431] [drm] Setting GART location based on new memory map
[167034.066436] [drm] Can't use AGP base @0xf8000000, won't fit
[167034.081321] [drm] Loading RV635 CP Microcode
[167034.081728] [drm] Loading RV635 PFP Microcode
[167034.096683] [drm] Resetting GPU
[167034.215462] [drm] writeback test failed 0 deadbeef
[167105.874990] [drm] Resetting GPU
[167105.969730] mtrr: MTRR 2 not used