TS4268 Why can't log into iMessage with my appleid

ok--so I went to log into iCIoud, on my iMac, and got a message that my password has expired and that I needed to change it. I did.

I am able to log into iTunes, the app store, FaceTime and iMessage on my iMac, Mac Book and iPad. I cannot however log in to iMessage on my iPhone 5. I am able to log into all the other apps and such.

The address is entered properly, as is the password. I am making sure that every key entry for my password is correct as I am entering it but after multiple, and I mean multiple, tries it still fails telling me that my username or password is incorrect. Again, this has only affected my iMessage.

Ideas?