.Net membership problem

Question

Hey everyone,
I'm struck with this issue since 2 days. I don't know why it doesn't work, but I used .Net membership for authentication.
The authentication part has been implemented as a service. In the web.config file, the maximum invalid login attempts has been
set to 3.
I logged into the app with admin credentials, created a user and tried to log in with the user credentials.
Even after 3 unsuccessful attempts, I could still log into the app. The funny part however is that when I tried to
log in as the admin with wrong credentials 3 times,  I was locked out.
Can anybody please explain this strange behavior??Am I missing something here?
I am trying to write unit tests for this case and  I just can't figure out what's going on.....