Comment 31 for bug 530348

Try this for your rule instead:

ENV{ID_SERIAL_SHORT}=="9QM42EXK", ACTION=="add", RUN="/usr/local/bin/backup %k%n drive1"

From the udev man page:

       The following key names can be used to match against device properties. Some of the keys also match against properties of the parent devices in sysfs, not only the device that has generated the event. If multiple keys that match a parent device are specified in a single rule, all these keys must match at one and the same parent device.

<snip>

       ENV{key}
           Match against a device property value.