Comment 1 for bug 64585

Vesa should probably work. Usplash was broken on amd64 at the time you reported the bug, and ati driver has the known problem of doing illegal detecting of the card (if you see the xorg.0.log ending in something like "Mach64 not detected", this's it.

What should really work as a workaround is to change "ati" to "radeon".