Well I just spent about an hour and a half playing with this but don't have a whole lot to show for it. First, for some reason, the “Ctrl+Alt+F1" hotkey hardly ever works for me which makes experimenting with this very slow and time-consuming. The next major problem I've run into is that no combination of video card and monitor in displayconfig-gtk seems to work for me -- even after manually replacing the driver line with Driver "fglrx".
The process you describe seems perfectly logical to me. Do you have any idea which specific ATI card I should choose in displayconfig (I have a Radeon X1900—and a Samsung 213T monitor)? For the combination of two or three Radeon drivers that I managed to try in displayconfig and the Samsung 213T, I can't succeed in getting the GUI interface to start up—even after putting Driver "fglrx" into the file manually. Also, is there any explanation for why “Ctrl+Alt+F1" just doesn't seem to work for me?
Thanks again for the help!