DVI monitor flicker with F10

[Chris Rouch]

Yesterday I installed F10 onto a spare disk. I installed over the
network with my LCD monitor (Samsung 240T) connected to the DVI output
of my onboard graphics card (ATI X1250). As soon as the initial tftp
messages had finished and the fedora installer started (with the
"network manager is configuring eth0" message), the display began
flashing on and off. I was using kickstart with vnc on, so I switched
off the monitor and let it complete the installation.

However booting the installed system has the same result. Everything
is stable until the point where plymouth starts (or the alternative
text output if rhgb is removed from the boot line), when the display
begins flashing again. This continues after the X display is started,
using Vesa or Radion (fglrx results in an immediate reboot, but that's
another issue). If I switch to the VGA output then the display is
stable, but offset to the left by about 40 characters.

If I boot back into F8 then everything is stable, so I'm sure it's not
a hardware problem.

Has anyone seen this or have any suggestions how to fix it?

Thanks,

Chris