I bought the same as bioeddie - ie a Maxtor 500gb External Hard Drive from PC World in Stockport, Greater Manchester, a few days ago. Connected it up and exactly the same thing happenned. Luckily I am running AVG anti virus which spotted exactly the same Trojan horse.
When I looked on the drive itself it contained the ghost.pif file as well as an autorun file.
I am returning it to the store tomorrow so I'll see what sort of reaction I get!