Weird Problem trying to sign into my App Store Account ? Please Help !!

Im having a very weird problem trying to sign into my App store account to update my apps and to purchase new Apps. Ive tried to search the net but I cant seem to solve my problem.

Here is whats happening

My Email address is correct in my iTunes Account and also my App Store account. (which is basically the same anyway)

The problem I am having Is that when I try to download an App my old email address still shows up when it requests my password.

The weird part is that my email address is correct in my itunes and also at the bottom of my app store. Yet my old email is showing up when I try to sign into the App store.

Here are the steps Ive taken already to fix this problem and have failed.

I have signed out of my itunes and app store and signed back in..FAILED.

I went into my setting -STORE and signed out and back in..FAILED.

I dont understand why my old email is still showing up when I try to sign in to update or download an App !!!!

PLEASE HELP !!!