Hey---so I tried searching for this and I apologize if this is redundant.
On the RAZR (my old phone) it didn't matter if you saved the number with/without area code, it still recognizes it as the same number but for some reason on my KRZR you can save a number with the area code but if you dial a number without it, it doesn't recognize it---same goes vice versa: if you save a number without the area code, when that person calls, it doesn't recognize the number.
It's really annoying.