No reply and I couldn't solve the problem so I went removing the package.
Just stopping the service didn't help… web browsing was extremely slow, that's why I tried removing the package completely and things got back to normal.
Then I reinstalled the package and it kept all my previous configuration, and it started doing the problem again.
Is there any way to make a clean remove and clean install of a package (or more specifically the squid3 package) ?
Thanks!