Comment 9 for bug 95241

As pointed out on the above ticket i suspect there is something odd going on at the proxy server, reacting in some bad way to something Firefox does.

The GMail notifier wont be sending the same UA string, neither will opera or firefox on windows or any other browser or http client. And given other reports also talk about this being an issue "at work", points more and more to a firefox<->proxy interaction in my opinion.