[plug] weird problem with a squid transparent proxy

[William Kenworthy]

I have a weird problem with a squid transparent proxy that has been
working fine up until about a week ago (thereabouts).

If I browse to www.shipito.com going through squid, I get a blank page
which is actually a "503, server unavailable" error from their nginx web
server.  This was fine previously.

If I bypass the proxy, everything is fine.  This is with firefox
(multiple linux and windows), IE on Win, and safari on an ipad -
definitely squid.

Is it my end, some change their end that I need to reconfigure for, or
they are explicitly detecting/denying proxied requests - wouldnt have
thought so.  Ive rebuilt squid, deleted/recreated the cache without a
change.  It is ONLY this site where I have the problem.

Perhaps if someone else using a squid tproxy could give me a sanity
check and say it is/isnot working for them I would be grateful.

BillK