I have recently purchased an iPhone 4 and am generally thrilled with it. My wife has one too and we have changed our ringtones from the default (SMS and phone) so we know we are calling. I have also changed my ringtones for other contacts, but the difference is that for every one apart from my wife's number they have been changed successfully. When my wife phones or texts they are 'stuck' on the default tones. The phone is not jailbroken and I haven't downloaded any custom tones - the phone is completely 'standard'. I have done the usual on/off stuff and a soft reset but, only for my wife's number, they still won't change from the default!! I could always change my wife, but I hope there is an easier fix ...