I am running pm-utils version 1.4.1-9git1ubuntu0.1 on Ubuntu 13.04.
I have configured my hard disks to spin down in /etc/hdparm.conf. These settings are working when the system is booted from S5 or when the system is rebooted. However, when the system is resumed from S3 or S4 the hard disks will never spin down.
I did some research and I found out the spin down settings are normally reapplied after resume by the script '/usr/lib/pm-utils/power.d/95hdparm-apm'.
The function 'resume_hdparm_spindown()' within this script checks if a device supports APM in line 65, before setting the spin down option. This is what is causing the problem on my system, which uses Western Digital WD20EARX hard disk drives. These drives do not support APM, but they actually do support spin down settings!
As a workaround I have copied the '95hdparm-apm' file to '/etc/pm/sleep.d/95hdparm-apm' and commented out the APM check.
I'm running a fresh installation of Ubuntu 13.10 amd64.
I have this same bug with a Seagate Barracuda 7200.12 ST3500418AS 500GB hard disk, which doesn't support APM but supports spin-down setting.
But I wonder why this bug was reported under pm-utils and not under hdparm, the package /usr/lib/