Comment 3 for bug 48053

I have the same problem with a Radeon 9200 PRO (see lspci output below). The workaround is to set your AGP speed to 4x instead of 8x in the BIOS. I eagerly await a better solution that will allow me to use 8x AGP.

See also:

http://lkml.org/lkml/2006/5/1/151

0000:01:00.0 VGA compatible controller: ATI Technologies Inc RV280 [Radeon 9200 PRO] (rev 01) (prog-if 00 [VGA])
        Subsystem: C.P. Technology Co. Ltd: Unknown device 2094
        Flags: bus master, 66MHz, medium devsel, latency 64, IRQ 185
        Memory at e0000000 (32-bit, prefetchable) [size=128M]
        I/O ports at a000 [size=256]
        Memory at fd000000 (32-bit, non-prefetchable) [size=64K]
        Expansion ROM at fcf00000 [disabled] [size=128K]
        Capabilities: <available only to root>

0000:01:00.1 Display controller: ATI Technologies Inc: Unknown device 5940 (rev 01)
        Subsystem: C.P. Technology Co. Ltd: Unknown device 2095
        Flags: bus master, 66MHz, medium devsel, latency 64
        Memory at d8000000 (32-bit, prefetchable) [size=128M]
        Memory at fce00000 (32-bit, non-prefetchable) [size=64K]
        Capabilities: <available only to root>