I've had other portable drives fall and survive without any issues, I just have a feeling that the Seagate FreeAgent drives are not among the most durable. I recieved a refurbished replacement with a 90 day warranty (so much for 5 years) and that drive has already failed. Spend a little more and you can find a drive designed to take a tumble here or there, just avoid anything coming out of seagate's product line up.
I saw it written somewhere that it is a 90 day warranty, but my friend just got a replacement sent to him when it was almost a year old. He says they really have one year warrantys. You ought to check it out. Im still trying to decide if i should break mine open and try to hook it directly to a SATA port on a computer.
Seagate provides a 5-year warranty for these drives, so if someone is trying to tell you it's shorter, or trying to sell you their own warranty, just keep that in mind. Warranty is void, however, if the drive is physically modified, disassembled, etc.
I'm having the same problem on my 1TB drive. I bought it today, used it once and my sister tipped it over and it's no longer working. I'm gonna try to get a refund at the store I bought it at.