Comment 11 for bug 435190

Here's a dirty work-around:

    ~$ cd /usr/lib/devicekit-disks
    /usr/lib/devicekit-disks$ sudo mv devkit-disks-helper-ata-smart-collect devkit-disks-helper-ata-smart-collect.real
    /usr/lib/devicekit-disks$ sudo sh -c "cat >devkit-disks-helper-ata-smart-collect <<EOF
    > #!/bin/sh
    > [ "$1" != "/dev/sdb" ] && /usr/lib/devicekit-disks/devkit-disks-helper-ata-smart-collect.real "$@"
    > EOF"
    /usr/lib/devicekit-disks$ sudo chmod a+x devkit-disks-helper-ata-smart-collect
    $ ls -l devkit-disks-helper-ata-smart-collect*
    -rwxr-xr-x 1 root root 99 2009-10-16 09:30 devkit-disks-helper-ata-smart-collect
    -rwxr-xr-x 1 root root 5608 2009-09-19 18:30 devkit-disks-helper-ata-smart-collect.real

Replace /dev/sdb with the device you don't want to spin up.