Suddenly my 3GS is having problems sending texts. For many correspondents in my Contacts, the text app is erroring out with response +1 121611611, "Error Invalid Number..." I have looked this message up and it is supposed to be caused by texting to a number with an area code. All of the erroring numbers have area codes, but the error message always prefixes a 1 to the number, as though the number were being dialed from a landline. All of my Contacts numbers are in standard 10-digit form, and when I tap the number link in the error message, it voice-calls the proper number. Has anyone else been getting this?