Prior to installing the restricted ATi drivers on an ASUS M51 laptop with an ATi Radeon HD 3470 GFX card, the system was usable from live-CD to installation. When I installed and rebooted, the display was scrambled and the system was unusable.
There are no back-ups for xorg.conf.
Starting from a live-CD seems to give the same problem now. I believe that by booting another system with the correctly (automagically, as before) configured display settings, it should be possible to copy this into the /etc/X11 directory. Does this sound right? Failed.
I should've posted this into the graphics card + monitors board. Sorry.
There seem to be many topics like this. It booted correctly from Ubuntu with the same problems with the resolution as I'd experienced before with Mint, but the system is completely usable.