added the Option "NvAGP" "0" to my xorg.conf Device section.
added intel_agp and agpgart to my /etc/modprobe.d/blacklist
I had a desktop with failure to resume from suspend.
ASUS A8N-VM CSM motherboard (nVidia onboard graphics)
Commenting this directive from /etc/default/acpi-support solves the problem.
1) Enable S1&S3 in BIOS
2) add a kernel parameter (acpi_sleep=old_ordering) to the grub boot options and update-grub
Basically, there are a bunch of jumpers on my motherboard to control USB wake-up behavior. Setting them to +5VSB (wake from S3 and S4) instead of +5V (wake from S1) gives me working suspend without the instant wake-up problem.