Finally downloaded Firefox 5.01 today on Mac OS 10.6.8. Even though I have multiple tabs open in the windows and have checked the box in Preferences; Tabs; "warn me when closing multiple tabs", when I close the open window, or shut down firefox, the windows close and the warning and the option to "save and quit" that appeared in the previous Firefox 3.6.6 version, does not appear. Is this feature discontinued? Or am I missing something I should do to continue having this option?

I am an avid firefox user for many years and I really do not want to change browsers now. Please give me some feedback Thank you