I have just been thru this...My old laptop had APM and SuSE 8.2 etc all had perfectly working standby (to memory, quickest)
and suspend (hibernate; to disk). New POS laptop is HP pavillion ZE4600, no APM, ACPI only. I read that some parts of
ACPI in hardware (BIOS + CPU) are still proprietary so Linux developers cannot get them working easily.
Result is: on my new laptop with SuSE 9.0 (2.4 kernel) suspend does not work, as is clearly stated in the SuSE release notes.
Furthermore it cannot easily be made to work with this kernel. The SuSE kernels are highly modified and patches like the
swsusp patch from sourceforge often/usually cannot be applied successfully. I got hundreds of "rejected hunks" when I tried this. Of course if you are a masochist you could try hand hacking every one of the hundred or so routines that the patch modifies, but I need to get work done not hack Linux.
SOOOO.....installed 9.1 which has working 2.6 kernel. My box has some specific problems with dsdt/powernow (see www.consultmatt.co.uk
for this digression). Anyhow with 2.6 kernel suspend does work. Standby does not work, per SuSE release notes.
My recommendation: SuSE 9.1.