When they upgraded to this version of the forums software, there was a "quick reply" feature added. It was like a red arrow on the top of every thread, it popped up a little reply box. You could click on "dock" and it'd dock the box at the bottom of the thread.
Recently, the quick reply box stopped working for Firefox users. There was mass outcry in FI, people assumed it was deleted (it wasn't), but they said it was "low priority". More outcry ensued, and it was fixed yesterday sometime.
I am glad it's back, even though I did find a workaround in firefox thanks to another member's suggestion. I'm not a huge fan of the "popup window to post" thing so quick reply is perfect for me. I do wish it'd parse URLs, but you can't have everything.