My account on Apple has different Alternate Apple ID than what my Ipad 2 has

I am so frustrated with my ipad; I can't take it! I have an apple ID that is my charter.com e-mail address and that is fine. When I am looking at my account on my desktop computer it shows a different 'Alternate ID' than what my Ipad 2 is showing. So, I am constantly being prompted on my Ipad2 to enter the password for your Apple ID; but the Apple ID that is reflected in this prompt is not accurate. Not sure if I can actually write what those 2 are but the one on my apple account as the number 13@me.com. The one on my Ipad is missing the '13' if that makes sense.

So, when I am prompted on my Ipad 2 to enter the password for my Apple ID (Alternate ID is reflected); I enter my primary Apple ID password and it says "The password you entered is incorrect". I tried changing my password on my desktop computer to a new password for my Apple ID but that did not resolve the issue. The Ipad2 wants a password but I have no idea what it is.

Anyone have this happen? Any resolution? Please help!

Michele