I'm having the same issue, but with only one of my contacts, to my knowledge... I've shut down my phone and back on numerous times, pulled the battery and tried to power up again, no change. Is yours with one of your contacts or most of them?
Strangely enough I am having the same issue with not getting texts or calls from one person. I thought the person was messing with me at first because I am receiving other texts and calls from my other contacts fine. Its just one person as far as I can tell. Does anyone have any input?
The issue for me ended up being in my friend's contact list. I'm apparently corrupt in his Android phone contacts. He's deleted my contact info altogether, re-entered me and the area code is not right after about an hour.
He's investigating further, but it will only work for about an hour after he changes it back to the right area code and will revert again. He's changed it through the gmail site also with no success keeping the data valid.