I’ve been keeping an eye out on Go Firefox! as well as mozillaZine. There seems to be a couple issues with some folks with the addons manager and secure websites. The biggest problem folks seem to be having is related to their Firewalls blocking Firefox 220.127.116.11. For firewall related issues check out: http://kb.mozillazine.org/Firewalls
For an easy to configure firewall I would suggest Sygate Personal Firewall. It is free and anytime an application tries to access the Internet or has changed since you last ran it, Sygate popups a box describing the issue and asking if you wish to allow this application to run. Simple ‘Yes’ or ‘No’ to configure with the option to remember your choice. Some folks may be annoyed with the popups, but I’ll take the popups over having the Firewall totally block the application.