Error at login: The information you have entered is not valid

Hi all.
After solving the issue with the connection problem (reset dns cache, change warmane.ru to com in the two different file ecc), when I enter my username and password in the wow client, it cannot complete the login procedure.
The error is "Error at login: The information you have entered is not valid" ecc ecc.
As first step I change my warmane password but the error is the same.
The login data are correct, I can enter withous problem to warmane site (I'm here writing this post so... ).
My connection issues are completely fixed, I have tried to use the account of a friend of mine and using his account everything is OK and I can get into the game. So my wow client work well.
The problem is whit my account data but I cannot understand why.

Someone has the same problem?
Someone can help me?