I have read other questions similar to my own that say click the return to default button on the customize page. I have done this, and yet the new tab button is still not where I want it. Instead it goes to the far right, which makes no sense (in my opinion). I try to move the button so it is next to the most recently opened tab, but rather than going where I want it, it goes to the far left! This makes using Firefox extremely uncomfortable, as I keep closing tabs by accident! I generally have 6+ tabs open at all times and this makes it very inconvenient. If someone could help it would be appreciated.