No joy, I'm afraid.
I have a desktop with a (cheap) 1600x900 LCD monitor.a couple of pets two messages above this one to install please, they should fix monitor selection and missing driver problems, Can someone try please and let me know results.
I started Mage-2.0.0.10 with a clean frugal and vesa at 1280x1024.
Installed your xorg pet and then tried the xorgwizard.
The radeonhd was now listed as a driver in <Choose> but the resolutions offered were not correct (no 1600x900).
Attempts to start X with the radeonhd driver failed at any tried resolution.
<Probe> doesn't find the right driver either.
One try using the ati ati option from the wizard <Choose> started at 1280x1024 but trying the resolution changer wizard option - 1600x900 was listed for this non-vesa 'success' - killed the graphics (black screen).
Once the graphics fail, attempts to recover with the videowizard fail ('xorgwizard' at the command line gets boring after while when nothing happens). Delete the Mage save file and start over with vesa is my only option.
I think it is the xorgwizard that is not quite right? - a radeon driver that works with other Pups is being listed by the wizard but it seems to then ignore the driver or doesn't have the right settings for it?
Sorry I can't help any further.
David S.