Using Windows Live Writer, I've been updating my blog (link in profile if you're interested - I won't spam it here), which runs Wordpress 3.6.1 on Debian Wheezy 7.1. I had ensured that /var/lib/php5 has 1775 permissions on the server, and gracefully restarted Apache2; no change.
I can access the blog just fine, and the control panel, from both Internet Explorer, and Firefox. Other people admit they can also access it, so I know the blog itself is up and running.
I also tried re-setting up my blog in WLW. It detects the blog, and settings, but still won't let me post! What else can I try?