While it's been some time since Seagate drives shipped in Apple machines, external drives or other machines may have them.... here's a description of the problem and a link to find out if your Seagate drive may be susceptible...

...from:
http://news.zdnet.co.uk/hardware/0,1000000091,39596623,00.htm

...and from:

http://seagate.custkb.com/seagate/crm/selfservice/search.jsp?DocId=207931

An issue exists that may cause some Seagate hard drives to become
inoperable immediately after a power-on operation. Once this condition
has occurred, the drive cannot be restored to normal operation without
intervention from Seagate. Data on the drive will be unaffected and can
be accessed once normal drive operation has been restored. This is
caused by a firmware issue coupled with a specific manufacturing test
process.

Support is available through Seagate’s call center, which can be reached by dialing: 1-800-SEAGATE (1-800-732-4283).

Seagate also says that customers can expedite assistance by sending an email (discsupport@seagate.com). The company asks that you include your drive's model number, serial number, and current firmware revision.

Thank-you,
Wayne Billing

Information Services and Technology

University of Manitoba