CloneMode problems on iBook G4

[Colin Leroy <colin@colino.net>]

Hi,

I'm trying to use my ibook's mirror mode. I plugged a Sony 210ES screen to to VGA adapter after boot and before X starts (else I get an openfirmware screen). 
The problem is that the CRT screen is set up with a mode like 320x240.

Any idea about what I do wrong?

My XF86Config interesting bits:

Section "Device"
 Identifier  "Card0"
 Driver      "radeon"
 VendorName  "ATI Technologies Inc"
 BoardName   "Radeon 9200 Mobility"
 Option      "UseFBDev"
 Option      "AGPMode" "4"
 Option      "EnablePageFlip" "On"
 ChipID      0x514d
 Option      "CloneMode" "1024x768"
EndSection

Section "Modes"
 Identifier      "Modes0"
 Modeline "1024x768" 100.000 1024 1040 1048 1064  768 784 792 808  -HSync -VSync
EndSection

I tried with other modelines, as well as no modelines. This doesn't change behaviour.

Thanks for your help,
-- 
Colin