[squid-users] squid + dansguardina https response on blocked url page

Hello i've a strange problem on my linux gentoo server (squid 3.1.16 +
dansguardian 2.10.1.1).
On my server dansguardian block http and https url correctly, but
in http mode url blocked have a correct users response html page,
response in https have a page error.
I don't understand why this uppens where the difference.

Example:

http://www.facebook.com -> users get a correct page feed back
https://www.facebook.com -> users get a page error

But dansguardiano blocked correctly http and https.

with https i obtain an proxy error like :

read into buffer; bufflen: 1024
HTTP/1.0 503 Service Unavailable
Server: squid/3.1.16
Mime-Version: 1.0
Date: Thu, 16 Feb 2012 20:27:38 GMT
Content-Type: text/html
Content-Length: 1246
X-Squid-Error: ERR_CONNECT_FAIL 111

Someone can help me please?
thank's a lot

-- 
Rispetta l'ambiente: se non ti è necessario, non stampare questa mail.
******************************************
Ing. Matteo Cazzador
Email: mcazzador_at_gmail.com
******************************************