Getting the "Login failed: user/password mismatch when using IE accessing the vco configurator page

When provisioning a vCO 5.5.2 appliance, I cannot log in into the configuration page https://:8283/ using IE as the browser. I continuously get the message: "Login failed: user/password mismatch or account temporarily blocked after too many unsuccessful attempts". But didn't changed the error message even after I changed the password. -Suresh