[squid-users] [squid 3.1.19] website loads forever when opened through squid

Dear all,

the following website is loaded forever by FF22 (also IE9) behind
a squid3 3.1.19 (stock Ubuntu 12.04 lts).
I can't find a reason why this happens, any ideas?

Thanks, in advance.

The config:

acl manager proto cache_object
acl localhost src 127.0.0.1/32
acl to_localhost dst 127.0.0.0/8 0.0.0.0/32
acl our_networks src 192.168.0.0/24 10.241.0.0/24
acl SSL_ports port 21
acl SSL_ports port 443
acl SSL_ports port 873 # rsync
acl Safe_ports port 21 # ftp
acl Safe_ports port 70 # gopher
acl Safe_ports port 80 # http
acl Safe_ports port 210 # wais
acl Safe_ports port 280 # http-mgmt
acl Safe_ports port 443 # https
acl Safe_ports port 444 # heise-svn
acl Safe_ports port 488 # gss-http
acl Safe_ports port 591 # filemaker
acl Safe_ports port 631 # cups
acl Safe_ports port 777 # multiling http
acl Safe_ports port 873 # rsync
acl Safe_ports port 901 # swat
acl Safe_ports port 1025-65535 # unregistered ports
acl apache rep_header Server ^Apache
acl CONNECT method CONNECT
acl QUERY urlpath_regex cgi-bin \?
acl PURGE method PRURGE
http_access allow manager localhost
http_access deny manager
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access deny to_localhost
http_access allow localhost
http_access allow our_networks
http_access allow purge localhost
http_access deny purge
http_access deny all
icp_access deny all
htcp_access deny all
http_port 192.168.0.44:3128
hierarchy_stoplist cgi-bin ?
# maximum_object_size_in_memory 64 KB
maximum_object_size_in_memory 256 KB
cache_dir ufs /var/spool/squid3 512 16 256
# maximum_object_size 8192 KB
logformat combined %>a %ui %un [%tl] "%rm %ru HTTP/%rv" %Hs %<st
"%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
access_log /var/log/squid3/access.log combined
log_fqdn on
ftp_user anonymous@
ftp_list_width 96
url_rewrite_program /usr/bin/squidGuard
url_rewrite_children 16
refresh_pattern ^ftp: 1440 20% 10080
refresh_pattern ^gopher: 1440 0% 1440
refresh_pattern (cgi-bin|\?) 0 0% 0
refresh_pattern . 0 20% 4320
request_header_max_size 64 KB
reply_header_max_size 64 KB
reply_body_max_size none
via off
extension_methods REPORT MERGE MKACTIVITY CHECKOUT
relaxed_header_parser warn
forward_timeout 2 minutes
cache_mgr webmaster_at_konrad-gmbh.de
visible_hostname proxy-dsl.konrad-gmbh.de
error_directory /usr/share/squid3/errors/German
acl FTP proto FTP
always_direct allow FTP
dns_timeout 20 seconds
dns_nameservers 192.168.0.20 192.168.0.15
hosts_file none
forwarded_for off
coredump_dir /var/spool/squid3

A small part of the log:
192.168.0.140 - - [09/Jul/2013:11:55:45 +0200] "GET
http://abz-bayern.etisportal.com/abz-bayern/layout/templates/images/de.gif
HTTP/1.1" 200 515 "http://abz-bayern.etisportal.com/" "Mozilla/5.0
(Windows NT 6.1; WOW64; rv:22.0) Gecko/20100101 Firefox/22.0" TCP_HIT:NONE
192.168.0.140 - - [09/Jul/2013:11:55:45 +0200] "GET
http://abz-bayern.etisportal.com/abz-bayern/layout/templates/images/en.gif
HTTP/1.1" 200 641 "http://abz-bayern.etisportal.com/" "Mozilla/5.0
(Windows NT 6.1; WOW64; rv:22.0) Gecko/20100101 Firefox/22.0" TCP_HIT:NONE
192.168.0.140 - - [09/Jul/2013:11:55:45 +0200] "GET
http://abz-bayern.etisportal.com/abz-bayern/layout/images/pqvol.jpg
HTTP/1.1" 200 3519 "http://abz-bayern.etisportal.com/" "Mozilla/5.0
(Windows NT 6.1; WOW64; rv:22.0) Gecko/20100101 Firefox/22.0" TCP_HIT:NONE
192.168.0.140 - - [09/Jul/2013:11:55:45 +0200] "GET
http://abz-bayern.etisportal.com/abz-bayern/layout/templates/images/help.gif
HTTP/1.1" 200 435 "http://abz-bayern.etisportal.com/" "Mozilla/5.0
(Windows NT 6.1; WOW64; rv:22.0) Gecko/20100101 Firefox/22.0" TCP_HIT:NONE
192.168.0.140 - - [09/Jul/2013:11:55:45 +0200] "GET
http://abz-bayern.etisportal.com/abz-bayern/layout/templates/images/shim.gif
HTTP/1.1" 200 412 "http://abz-bayern.etisportal.com/" "Mozilla/5.0
(Windows NT 6.1; WOW64; rv:22.0) Gecko/20100101 Firefox/22.0" TCP_HIT:NONE
192.168.0.140 - - [09/Jul/2013:11:55:45 +0200] "GET
http://abz-bayern.etisportal.com/abz-bayern/layout/images/network.jpg
HTTP/1.1" 200 7876 "http://abz-bayern.etisportal.com/" "Mozilla/5.0
(Windows NT 6.1; WOW64; rv:22.0) Gecko/20100101 Firefox/22.0" TCP_HIT:NONE
192.168.0.140 - - [09/Jul/2013:11:55:48 +0200] "GET
http://abz-bayern.etisportal.com/ HTTP/1.1" 200 5706
"http://abz-bayern.etisportal.com/" "Mozilla/5.0 (Windows NT 6.1; WOW64;
rv:22.0) Gecko/20100101 Firefox/22.0" TCP_MISS:DIRECT
Received on Tue Jul 09 2013 - 13:44:19 MDT