i bougt it new:)your friend from vf was half right.in my home country the phones are loked because you can get them at a cheaper price but with a contract(1 year or 2 years).so is normal that if a telco is giving you a cheaper handset it will expect from you to use its services:) also companies sign exclusivity contracts. for example blackbery storm 2 will launch exclusively for vodafone in some markets in europe.
vodafone qatar doesn't lock its phones because they don't sell their connections with contracts.maybe it s a question of the type of sim that you have from qtel...