This is with squid-2.5.STABLE3-6.3E.8 Squid doesn't cope with HTTP response headers which are split across different TCP packets. Observed proxying to http://www.iii.co.uk/ Produces the following error (intermittantly): 2005/03/10 10:59:01| WARNING: unparseable HTTP header field near {: Thu, 10 Mar 2005 10:58:59 GMT Server: Apache/1.3.22 (Unix) AxKit/1.4_82 mod_perl/1.26 mod_gzip/1.3.19.1a Vary: X-HOST Expires: now Pragma: no-cache : no-cache,no-store,private Content-Type: text/html Content-Encoding: gzip : 18064 } The missing parts of the headers are being sent by the origin server but are lost by squid. This is a known issue and the patch to fix it is available at: http://www.squid-cache.org/Versions/v2/2.5/bugs/squid-2.5.STABLE7-split_headers.patch I've tested this and it applies cleanly to the current SRPM and fixes the problem.
The new release-candidate packages for RHEL3/4 are available here: http://people.redhat.com/stransky/squid/
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2006-0045.html