I installed adblock and when is running (with no proxy settings) doesn't block any ads. In the notification bar it doesn't say "listening port..." or something similar:

"Ads blocked in all conections"
But then, I changed the proxy settings (localhost, 2020) and several apps doesn't work. For example:

I used port 2020, 80 and others and it's the same. It doesn't block ads or block all the internet. What can I do?
Thanks.