[masraum]

OK, I just checked. When I close FF down, it gives me the "close multiple tabs" confirmation dialog. I accepted. Then, the next time that I open firefox is pops a small white box up in the middle of the page that says "restore previous session". I click that box and it opens the old tabs.

I liked the old option, but that's probably just because I'm used to it. I think the benefit of the new way is that if you accidentally close a window down, you've got a better chance of getting your previous session back.