Sent a 4 month old 500GB seagate back last month that was behaving the same way. I didn't know there was a fix out there.
Ran "sea-tools", it said the drive was bad, gave me an error code & I RMA'd it.
If you haven't yet, check out their crazy return instructions.
They basically require that you use very specific packing material, but they won't provide it for you.
They provide a link to a company that sells the stuff, but it isn't worth the cost to have it shipped to you.
....and if they don't approve of your return packaging, your warranty is void.
I had some leftover rubber foam from a project that wasn't too far from what they required.
They shipped me a new drive A WEEK after receiving my old one. UPS showed my old drive was delivered on a Friday morning and my rma status on the seagate website was still "awaiting your drive" the following thursday. I sent them an email inquiry & within a few hours it was updated to received & the new drive was shipped out the next day. Then I received a reply to my inquiry that stating that the new drive had already shipped. I figure it would have taken even longer had I not inquired.
The crazy thing is that they specifically request that you not use bubble wrap or packing peanuts (or newspaper), which is exactly how newegg shipped the drive to me.
They do offer an option to pay $20 and they'll ship you a new drive, then you ship the old one back in the same box.
At that point, you're pretty much buying a new drive anyway, making the warranty worthless.
I doubt I'll buy another Seagate unless it's a super deal.