i had a very similar problem but i only had call problem.

my sim card was 3 years old and it would only let me call and not send msgs using the iphone and my nokia would work with both sms and calls then when i switched back to iphone the simcard stopped working and even in my nokia i could only send sms

so i called my carrier and they said it was all fine and i could come in for a free sim card change. so i did and it all works now

EDIT
i was never able to recieve calls from just one friend