One of the more recent updates to Firefox started to popup a message whenever I access StackOverflow from my work machine, along the lines of:
'The proxy moz-proxy://xxx:8080 is requesting a user name and password. The site says: "moz-proxy://xxx:8080"
The message consistently pops up 6 times, I can cancel all of them and the page looks fine. If I change to another SO page I get the same issue.
This is not a problem in Explorer and I haven't found any other website that gives me this problem - it's most irritating because SO is my first port of call for tech issues! I've had a hunt round the web and there are a couple of config suggestions (network.proxy.share_proxy_settings=false and network.automatic-ntlm-auth.allow-proxies=false) that I have set but they make no difference. I am out of my depth here!