Status bar is no longer available and FF no longer fills the screen?
The option to have a "status" bar at the bottom of FF is no longer available. I see status being shown when I change webpages, etc. but the bar is no longer available from toolbar options. Since my previous version of FF had a status bar, I now have an empty space near the bottom of my screen where the status bar used to be. Full screen is the only other option to have it go to the bottom of the screen.
If you want the features/appearance of the status bar you can regain that with an extension, if you just want to hide the bottom area where the status bar had been and is now called the addons bar you toggle it off or on with "Ctrl+/" described in item #10 of the following;
To better understand the changes that were made so you can decide what parts of either that you want or don't want see ...
You can make Firefox 6.0 look like Firefox 3.6.*, see numbered items 1-10 in the following topic Fix Firefox 4.0 toolbar user interface, problems (Make Firefox 4.0 thru 6.0, look like 3.6). Whether or not you make changes, you should be aware of what has changed and what you have to do to use changed or missing features.
Please mark "Solved" one answer that will best help others with a similar problem -- hope this was it.