Is it possible to login to facebook using an inactive yahoo account?

[daph]

Someone has created a fake profile of my friend on facebook and we have found the id used to login is a yahoo id. We cracked the id and on searching for that id on facebook, we get the same fake profile. But when we try carrying out the forgot password procedure on yahoo for the same id, yahoo says the id and code combination is wrong. (The code is the text which we have to read and copy)
No, I don't know the password. I have just figured out the email id. On searching for it on facebook, the same fake profile opens. So the email id used by the fraud is correct.
But when we try doing the forgot password thing, yahoo says the username and code combination is wrong. Has the id been deleted due to inactivity?