When you unlock them for another network you have to configure the correct APN to match the SIM your using.
For example:-
3
Internet
APN: 3internet
IP address: Leave blank
Username: Leave Blank Password: Leave blank
BT Mobile
Internet
APN: btmobile.bt.com
IP address: 212.183.137.12
Username: bt
Password: bt
URL: http://wap.btmw.net
O2
Internet
APN: mobile.o2.co.uk
Username: mobileweb
Password: password
Primary DNS: 192.113.200.200
Secondary DNS: 192.113.200.201
SMTP gateway (for email): smtp.o2.co.uk
Orange
Internet
APN: orangeinternet
Username: Leave blank
Password: Leave blank
Primary DNS: 193.035.131.194
SMTP gateway (for email): smtp.orange.co.uk
T-Mobile
Internet
APN: general.t-mobile.uk
Username: user
Password: pass
Primary DNS: Set automatically
SMTP gateway (for email): smtp.t-email.co.uk
Vodafone
Internet
APN: internet Username: web
Password: web
Primary DNS: 158.043.240.004
SMTP gateway (for email): smtp.vodafone.net
Social Networking Bookmarks