Optus iPhone SMS Not Sending
OK... The above post I made was only a temporary fix (as I found out).
Turning onto flight mode helped, but not completely. Plus, I didn't want to have to do that every day!
So - after speaking to an Optus (Australia) tech person, and doing a full reset of the phone (holding home button and on/off button for about 10 seconds till you see a white "apple" symbol on the screen...)
It worked.
But then it didn't again.
Turns out that my SIM card was from 2006, and the iPhone likes "newer" sim cards. I went to a local optus store & they changed the SIM card to a brand new one... (at a cost - which you can redeem from optus)
The difference? The contact plates (goldy coloured things) on the back of the new SIM card were slightly different in shape, and that's pretty much it.
Now it fits, perfectly - and I have way better reception than before...
Yeh. Hope that helps you!
Cheers