I have an Airport Extreme which has a USB disc and two printers hanging off it.
The Disc has two partitions, one of which is a Time Machine backup; the other has some shared files.
Time Machine causes the disc to spin up every hour, and sometimes when I use the Finder or an Open Dialogue, the disc will spin up to access the other partition. In either case the disc spins down after about 30 seconds of idle time.
Since installing 7.6 firmware, the USB disc spins up every couple of minutes, and as soon as the disc heads have loaded and the disc has finished rattling - perhaps 2 seconds after the whirring has reached running pitch - it spins back down.
I've done all the obvious - rebooted all the Macs sharing this disc, rebooted the Airport, powered down the disc and added it back in. All to no avail.
Does anyone else here see the same behaviour, or is this just a horrible coincidence occasioned by something else I may have changed?
I've also downgraded to 7.5.2 and the peace and quiet is now disturbed but once an hour when Time Machine wakes up the attached USB disc, instead of every 2-3 minutes winding the disc all the way up and instantly all the way back down again. Bliss!