radeon 8500 mergedfb flicker

[Dave Airlie]

I'm running a Radeon 8500LE with dual head DVI->VGA plugged into a 17'
CRT and a VGA  15' flat panel on the VGA connector.

I'm running the montior at 1152x864 and the flatpanel at 1024x768.

I'm seeing some flicker on my CRT when I scroll a window on either
screen, shadowy dark flickery bands appear at different points across
the screen....

My config file is at
http://www.skynet.ie/~airlied/radeon/XF86Config.radeon_mergedfb (with
the 1152x768 replaced with 1152x864..)

Is this a bus bandwidth issue or something like that? should I give up
my dream of dual head  3d and go back to using a PCI card for the
second head?

Dave.