I was one of the unlucky ones who got caught with the Qantus shutdown, so while I was sitting around for two days at the airpport I played with my Samsung SII I900
Some how I managed to turn something off as it was working fine just before as I sent quite a few messages out, then getting bored, I started going through the menus trying this and turning Off /On that..!
I can still receive message but can not send any messages they all come up with Fail Send errors..
Help I promse not to play with it anymore!!!!