Discovered in the late fall, a firmware problem in Seagate's Barracuda 7200.11 platform can result in your drive "becoming inaccessible after a power-off/on operation," or in other words, becoming an expensive brick. The company offered a fix but it required a Windows machine. Now, there's a process for Mac users.
I pointed out this issue with Barracuda 7200.11, Barracuda ES.2 SATA, and DiamondMax 22 drives
back in November. And since then, I have been pinging their tech support about a Mac-related fix — their support tools and firmware update required a Windows machine.
MacTech on Wednesday offered a pointer to Seagate's solution
. Still, it will take some digging and the final solution is far from Mac-elegant.
The Seagate Knowledge Base document is titled Firmware-Empfehlungen für die Festplatten Barracuda 7200.11, ES.2 SATA und DiamondMax 22 
Owners can see the full model number and serial number of connected ATA drives by clicking on Serial-ATA in the Hardware menu of the System Profile utility. However, it won't give you the firmware version (unlike SCSI drives, for those readers old enough to have used them).
Seagate says to check the drive in its online model number tool and serial number tool, which will tell you if your drive needs a firmware update.
There's a list of drives and links to download pages, however, I'm unsure if these updates are the correct ones for the power-off/on issue. According to the MacTech report and the response that I received from Seagate previously, users should request the firmware update.
The firmware update comes as a ISO image file. You burn a CD with the image using Disk Copy and then boot the disc by holding down the Option key. The disc boots into FreeDOS and launches the updater.
There's a good rundown of the experience by Armando Accardo in an Apple Support discussion thread
on the subject.