At work, all requests are forwarded to a central load-balancing, caching Squid proxy server. If I try to access Facebook from within Firefox, I get the standard proxy authentication dialog:
The proxy moz-proxy://<IP addresss> is requesting a username and password.
The site says: "moz-proxy://<IP Address>"
However, this dialog comes only for facebook & only when accessed from Firefox - any clues as to why this happens? Accessing from Internet Explorer or Chrome works fine, and yes Facebook is not blocked.
Just Firefox gives this problem. I have installed NTLM Auth for Firefox addon, but it hasn't helped.
The proxy settings are set to auto detect, same as in Internet Explorer & Chrome.
I'm using the current stable version of Firefox, 10.0.2 on Windows XP SP3