Comment 40 for bug 559163

Disabling KMS per these instructions (https://wiki.ubuntu.com/X/KernelModeSetting) prevented the machine from suspending at all. From pm-suspend.log:

/usr/lib/pm-utils/sleep.d/99video suspend suspend:kernel.acpi_video_flags = 0
--quirk-no-fb passed, but system is using a framebuffer.
Aborting.
Returned exit code 1.
Wed Aug 18 11:18:52 EDT 2010: Inhibit found, will not perform suspend
Wed Aug 18 11:18:52 EDT 2010: Running hooks for resume

Blacklisting radeon does not seem to have any effect either.

Any suggestions for further action would be welcome.