[ltp] Can't set resolution of second monitor above 1024x758

[Phil Shotton]

T60, ATI Mobile Radeon X1400, using ATI proprietary driver v8.4.33 (the 
latest) in Ubuntu Gutsy. I have twin-head configuration using laptop 
(lvds) and external LCD (crt1), with desktop extending across both. 
Device section looks like:
Section "Device"
        Identifier  "aticonfig-Device[0]"
        Driver      "fglrx"
        Option      "DesktopSetup" "horizontal"
        Option      "OverlayOnCRTC2" "0"
        Option      "VideoOverlay" "on"
        Option      "OpenGLOverlay" "off"
EndSection

The external LCD supports DPMS and has max resolution of 1280x1024, but 
try as I might I cannot get it to display in higher than 1024x768 which 
looks crap.

Has anyone got twinhead working at higher than 1024x768 on external?

Thanks
Phil