I would have thought seagate would have had this resolved by now, but their 7200.11 drives used to have firmware issues that prevented them from being seen. This was around early 2009.
These were the drive models and firmware revisions effected. The models start with "ST"
Barracuda 7200.11 ST3500320AS
ST31000340AS SD15, SD16, SD17, SD18
Barracuda 7200.11 ST31500341AS