Dear, Pix and INDRANIL! Many thanks for your trust to me 🙂 But I can’t to say more than Pix already said. If INDRANIL inserts the same SIM card in all mobile and only K660i was unhappy then most likely it is Sony Ericsson drawback.
INDRANIL, if you want to learn Manual Network Selection Procedure deeper then see 3GPP 23.122. Also, I want to ask you. How does K660i present the 2G and 3G PLMNs for the same operator, when it shows the list of PLMNs/access technologies for manual selection?