The basic Firefox build has always opened a blank tab when you open a new tab. Something that you installed added that feature to Firefox, and now that add-on is probably disabled, due to "compatibility". '''{ Ctrl + Shft + A }''' > Extensions <br /> At the bottom of that list, what extensions are disabled? If it is the Google Toolbar extension, I don't think Google is going to continue with supporting Firefox in the future. Their new Google Toolbar 8 version looks like it is only made for Internet Explorer. <br /> http://www.google.com/support/toolbar/bin/answer.py?hl=en&answer=1111588#toolbar_info You might want to ask Google about that.