When I start Firefox, all is well. However, when I close the first window, the Menu Bar items (FILE, EDIT etc. disappear. The word Firefox is still visible as are all the other Mac icons on the right end of the bar. Clicking on the Firefox icon on the dock while Firefox is running does not open a new window whether in Firefox or in Finder, but clicking on a HTML icon on the desktop will open a new window and go to the site. The Menu items may or may not appear, but the drop down menus are still active. I just looks like the Menu headings (FILE EDIT etc) are invisible. I reiterate that Firefox is open and still active (the name is at the left end of the Menu Bar). I have reinstalled the most recent version of Firefox. Running 10.7.5 Firefox 26.

It is irritating to have to Quit and re-open Firefox every time a want a new window after closing the previous.