From what you have described it seems that the username and password are correctly set in the db. As a test of this you can put the attached file into your admin area and browse to it. You should only run this test locally, this file should not be uploaded to a live server since it will tell whoever looks at it the username and password for the admin area.
Please give this a try to see if the values match what you have in your db. Let us know how it works for you.