Comment 12 for bug 1073137

I can confirm the same behavior for Ubuntu 12.10 AMD64 on an ASUS P8B75-V. My boot drive, sda, is an ssd.

The four mechanical drives run through a single pci/IDE interface.

 sda: OCZ-VERTEX4 (1.5) (ssd, not an issue)
 sdb: Seagate ST380011A
 sdc: Maxtor 6L020L1
 sdd: Maxtor 6E020L0
 sde: Hitachi HDS724040KLAT80

All mechanical drives spindown 60 seconds after signon, as configured in the 'Disks' gui (ver 3.6.1).
All mechanical drives reliably respond to 'sudo hdparm -S 12 /dev/sdb' (as do sdc,sdd,and sde).
All mechanical drives remain asleep until user or program access.

When NOT configured to spindown in 'Disks', all mechanical drives do not recognize/respond to commands in /etc/hdparm.conf:

 /dev/sdb {spindown_time=12}
 /dev/sdc {spindown_time=12}
 /dev/sdd {spindown_time=12}
 /dev/sde {spindown_time=12}

Also, after a suspend/resume powerdown, all mechanical drives no longer spindown again unless commanded to in terminal or the 'Disks' gui.