[squid-users] error:invalid-request

Hi,

From my squid (version below) a user visits microsofts site and
tries to reach its virtual lab . AND this site redirects to other
external sites. After a while the users screen starts to wait at
connecting. When i look at the proxy log for the user i see that
attemps are TCP_MISS and http and https (which the proxy gives service
generally) and just last log entry is below . What does it mean , is
there a problem with that site?

Regards

TCP_DENIED/400 1760 GET error:invalid-request - NONE/- text/html
    : squid
Version : 2.6.STABLE21
Release : 6.el5
Received on Wed Sep 12 2012 - 13:53:09 MDT