Comment 118 for bug 89853

>>I am trying to install Feisty on a Dell Optiplex 745 with a Radeon X1300 Pro.
>>This bug prevents the installation from going forward because the X display
>>starts up, but at 800x600, and starting with the VERY FIRST dialog of the installer, selection of the language, the "Next" button is further than 600 pixels down the page.
>>The dialog cannot be resized any smaller.

Now it seems irrelevant, but you can always move the windows so that the buttons are clickable. You can press Alt and simultaneously click in any point of the window, and move the mouse without releasing the mouse button.

I had to install in 640x480 mode and it worked. After instalation I switched to fglrx and everything worked fine (except AIGLX, of course).