I've always (and still do) blocked plugincontainer.exe from internet access in both my firewall & Sandboxie settings. I do allow it to start/run though. I've never noticed it need internet access for anything to function properly, and my rule of thumb is always to block in that case. Since the update to 13 I notice I get a Sandboxie pop-up about it's internet access being restricted whenever I try to watch a Youtube video... perhaps every flash video now (haven't tested it that thoroughly). The video still runs just fine regardless though. Also when I close Firefox I get the same pop-up. Don't ask me why plugincontainer would have to access the internet for Firefox to close?... Everything still works just fine without granting it access. It's just a nuisance. Is their plan to try to irritate people into granting it access?