iphone using wrong apple id for updates

This has been working in the past but today it is not. I have updated to iOS software 7.1 (11D167) but I don't know if that caused this problem. I only know that I have successfully installed software updates in the past but when I tried today I could not.

I have 5 apps showing as needing updates. They are Bing Search, Lose It!, Yellow Pages and Ancestry. When I try to update all or even each one individually, it prompts me to sign in to iTunes Store and asks for the apple ID password and shows my apple id. What is showing is a very old ID and not my full email address. When I put my apple ID password in it does not recognize it.

I then decided to try and install a new app and see if the app store would have the correct apple ID. When I selected to install the new app, it prompted me for my apple ID password and had the correct apple ID (my full email address showing). I entered my apple ID and the install proceeded successfully.

I saw on another post that there might be old apple IDs in settings for messages, itunes store, etc. so I checked those settings and all of them have my correct full email address for the apple ID.

What's mostly frustrating is that these apps were free to start with so why do I have to enter in a password at all for the updates?

Does anyone know why my phone has reverted to an old apple ID for app updates only, and why now when it was working before? Is there a way I can get apple to destroy any reference to my old unused (and now unacceptable format) apple ID so that it won't pop up to haunt me again?

Thanks for any guidance...