Brian, I came across your post because I had the same problem, I installed an evaluation copy and forgot the admin password. Following the instructions in that link alone did not work, but here's what I had to do:
As well as setting "password_format = 0", I had to set the salt = NULL, set the failed_password_attempt_count = 0, last_lockout_date = 0, is_locked_out = 0, and finally what did it was setting is_logged_in = 0.
I'm not sure if all of these are required or if "is_logged_in" was all that I had to change, but this combination of steps worked for me.
And following the instructions to reset the password did not work for me either, I would press reset and would get a confirmation dialog asking me if I'm sure I want to reset the password, after pressing yes, nothing happens. To resolve that I just created a new user, and manually copied the password and salt generated for it and put them on the admin record, and don't forget to set the format back to 0.
I know it's very late and Telerik didn't help you here, but I hope that was helpful to you!