using acl patterns

Hi, Squid Users.

I've a problem using patterns with acls.
The problem is that squid seems to not check patterns included in
host name field of the url.

For example the following acl set:

acl example pattern yohoho
http_access deny example

does not block access to http://www.blahyohoho.com/, but blocks the
following url: http://www.blahyohoho.com/xyohoho.

Is it possible to solve this somehow?

I'd like to block access to some www sites (sex, porno, erotic)
just not to pay for extra traffic. May be this will not help -
we'll see.

-- 
Alexander Serkin, Moscow Cellular Communications
                  "You know, you shock me, baby,
                   You shock me all night long..."