now follow these steps
1. open the menu
2. go to messagig option
3. dont go to any folders and open settings for text messages.
4. select the message centre for your service
try sending msg again it would surely go.
this happens as you might have changed the sim card and used the msg srvc. the phone would have configured itself for that srvc and would be using the message centre of the same old srvc but with this card. if u still have difficulty contact me on email@example.com
have you experienced bugs with your nokia 6600?
just recently (after 6 months of usage), i could not send text messages (sms) with my nokia 6600. at first sms gets a "Resend" status, but eventually to "Failed". i tried sending sms with my sim from another model/phone and twas sent successfully. so i believe, something's really wrong with my phone.
what could be the problem?