[squid-users] unable to connect to ssl site: google+

Dear list

Today I ran into a problem, which I am unable to solve myself. Almost
all ssl sites work well. For instance I can browse to
https://banking.postbank.de or https://epetitionen.bundestag.de/
without problems. However I am unable to connect to google+
https://plus.google.com, getting: "The connection has timed out".

While browsing to i.e https://epetitionen.bundestag.de/ I get in my access_log:
1325006076.306 0 192.168.2.104 TCP_DENIED/407 1733 CONNECT
epetitionen.bundestag.de:443 - NONE/- text/html
1325006076.311 0 192.168.2.104 TCP_DENIED/407 1903 CONNECT
epetitionen.bundestag.de:443 - NONE/- text/html
1325006076.633 0 192.168.2.104 TCP_DENIED/407 1709 CONNECT
sdc.bundestag.de:443 - NONE/- text/html
1325006076.699 2 192.168.2.104 TCP_DENIED/407 1879 CONNECT
sdc.bundestag.de:443 - NONE/- text/html
1325006076.817 112 192.168.2.104 TCP_MISS/200 1446 CONNECT
sdc.bundestag.de:443 schueler2 DIRECT/217.79.215.173 -

While browsing https://plus.google.com I get:
1325006240.062 52 192.168.2.104 TCP_DENIED/407 1706 CONNECT
plus.google.com:443 - NONE/- text/html
1325006240.066 1 192.168.2.104 TCP_DENIED/407 1876 CONNECT
plus.google.com:443 - NONE/- text/html
1325006240.119 49 192.168.2.104 TCP_MISS/404 0 CONNECT
plus.google.com:443 schueler2 DIRECT/- -

I am running Squid Version 2.7 on an ubuntu 10.04 LTS machine. User
authentication is done via NTLM against an AD, using the
wbinfo_group.pl script. I have attached my squid.conf to this mail.

My first questions is if course: Whats the reason for the google+
request failing?
My second question is why I see three log file entries for each ssl
request. Two unauthenticated ones and the third one authenticated?

Thanks for all your efforts.

B. Brandt