iPhone Removing International Dialing Code

[Snifferq]

I'm using a sim card designed for roaming in an unlocked iPhone purhcased in Australia and can't send texts to Australian numbers. If I try to text a UK, Irish, French etc phone it sends fine but not to Australian numbers. Even if the contact is saved as +61 in the phonebook the message still sends from the phone without this, i.e carrier call records show that the message was send to a 04 number where they should show it sent to 6104. Meaning of course, the text doesn't deliver as you're on a romaing network it won't have a clue where to send a text to 61 to - the SMS will send from the phone but because the dialing code was removed it won't deliver. Can call the same number by dialling +61 but if I input +61 in when sending the text the phone keeps removing it.

I can only assume that the phone thinks the code is not needed to deliver the message so keeps removing it? Anyone come accross this before and know how to stop it?

Have tried changing number saved in the phone to include the dialing code
Manually inputting the phone number when sending SMS
Turning off dial assist incase this was the issue

If I put the sim in another phone and send a message to Australia it delivers without any problems, so it's something on the iPhone that's doing this. Have asked on Apple support but can't get any response on there.

Any ideas?

[peterb]

Localization settings maybe? Phone 'thinks! It is in Australia.

[burble]

Does it make any difference if you turn off 'dial assist' in Settings -> Phone?

I don't know if it'll make any difference but it's worth a try.