I have no idea I didnt install it. I simply looked for you a way to get the username and password from the admin database. If you get that username and password and it still wont let you log in then I would say it doesnt work and ask for a refund.
I often find issues with hashed values in pre-loaded scripts. It comes down to how the password was encrypted during INSERT or UPDATE to the table.
A quick work around is to just get to a command line and update the password in the database or, if the author used PHP, write a quick script to get the job done. Of course, you'll have to have a peek inside the author's code to find the password update or insert routine and use the same SQL code you find in the script. For example, if the author used PHP's md5 function, you need to do the same.