Just noticed something with my 200M running radeon with KMS enabled. If KMS is on I can't select other resolutions besides the native dimensions. I have checked xrandr and it only lists one mode. If I disable KMS there is no problem.
Screen 0: minimum 320 x 200, current 1280 x 768, maximum 4096 x 4096 VGA-0 disconnected (normal left inverted right x axis y axis) LVDS connected 1280x768+0+0 (normal left inverted right x axis y axis) 305mm x 183mm 1280x768 60.0*+