FireFox Preventing BitBucket.com Account Log On

I am unable to log in to my bitbucket.com account via FireFox 3.6.15

No problem when using IE6 or Google Chrome 9.0.597.107

Forbidden (403)
CSRF verification failed. Request aborted.
You are seeing this message because this HTTPS site requires a 'Referer header' to be sent by your Web browser, but none was sent. This header is required for security reasons, to ensure that your browser is not being hijacked by third parties.
If you have configured your browser to disable 'Referer' headers, please re-enable them, at least for this site, or for HTTPS connections, or for 'same-origin' requests.
More information is available with DEBUG=True.