iMessage on iPhone 3Gs being used as an ipod
I have an issue. I upgraded to the 4Gs, gave my wife my Phone 4 and plan to use her old 3Gs as an iPod touch for my son. Here's the issue I'm running into. I created an iCloud email for my son on order to use iMessage for free texting. The 3Gs which has been upgraded to ios 5 still shows my wife's phone number as an option to receive iMessages at. Obviously this is a problem because if I send a text to my wife or my son it goes to BOTH phones. I'be removed the sim card from. The 3Gs and even deleted the phone number from the 3Gs but it does not remove her phone number. You also cannot delete her phone number in the iMessage options for receiving texts.
Will I have to set the phone up as new in order to correct this issue?