iMessage still showing old number after porting

[Lara F]

So I finally ported my old AT&T number to my Verizon iPhone 4 yesterday after installing iOS5 on Wednesday. I've just noticed now that it still has my old number listed in the iMessage settings, and it's greyed out.

There must be a way to fix that? Help!

 

[Richdmoore]

My brother had both his old and new phone receiving iMessages. He simply had to turn iMessage off, then back on with the old phone to make it stop.