Comment 54 for bug 58721

Update: I have discovered that the flickering problems are associated with the framebuffer. (Perhaps because my AGP 1x interface is too slow?) The flickering is subtle but can easily be seen by clicking on the "Quit" icon to exit Ubuntu while you still have a terminal window open, or any other large black spaces on the screen. These will go crazy colours and dance around a bit...

However, if I disable the framebuffer in both xorg.conf and /etc/modules and try what Thomas did in his original post, i.e. replace "mga" with "vesa", it works! Not only pristine 1280x1024 text but glxgears too. (Ahem, please don't ask about the frame rate. :) One small issue: if I go into Display Settings and change the resolution, X crashes.

Someone please reassure me that when the mga driver is working properly I won't need the framebuffer.