Re: Suspend/Hibernate - does it work for you?
One thing to note with ACPI power management on Linux is that mileage still varies greatly between different hardware and, unfortunately, software configurations. A lot of active development is still being done in the Linux kernel and behavior with any two Linux kernels can be drastically different.
If ACPI S3 and/or S4 do not work with a given configuration, it's worth checking if it reliably suspends/resumes without the NVIDIA Linux graphics driver (and the NVIDIA kernel module) loaded, either from within X with the nv X driver or (preferably) from the console, before X has started. If this works reliably, power management problems with the NVIDIA graphics driver are more likely to be caused by bugs in or interoperability problems with the latter, but since the NVIDIA graphics driver interacts with the kernel and the host system differently than the nv driver, it relies much more heavily on a reliably working host system, and often exposes problems that would not be seen otherwise. An example is power management in the AGP GART driver, which, unless properly implemented, can result in hangs if the NVIDIA graphics driver was configured to use AGP memory. This still is a common problem today.