Still loving this extension BUT although I dont have the "link-click" problem in previous comment, this version does corrupt my start-up page.
My short cut for Firefox includes the URL for my google calandar so when it starts it goes straight to it. With this version of your extension, Firefox starts and you can see the correct URL in the address bar momentarily, but then your extension over-writes it and you get the New Tabs page.
Hardly life changing - I just hit the home button which is also set to my google calandar URL - but proof positive that "you fix one problem, and create another" !