STFU && RTFM

My girlfriend recently got herself a shiny new MacBook Pro, and installed Firefox, as that’s her browser of preference. She kept having a problem that her tabs would not be saved when she closed Firefox, and asked me to look into it.
 
All the settings under Preferences were OK, so the problem was not with the settings. Likewise, the relevant settings under about:config were set correctly. We tried deleting prefs.js, but that didn’t help either.
 
Then, as a last-ditch attempt, I tried closing Firefox using the option on the menu bar. I then got the beloved question “Do you want Firefox to save your tabs”. I clicked yes, then restarted Firefox. All the tabs were reloaded. I then used the red X in the upper right-hand corner, the opened Firefox, and the tabs were not reloaded.
 
I registered the bug with Mozilla (bug #544880), and it seems like this is not so much a bug, as the way Firefox is handled in Mac OS X; when you use the red “x”-button, it does not shut down Firefox, but rather closes the window in question.

One of the reasons why I absolutely love Mozilla Firefox is the fact that the system of tabs is so excellently implemented. At times I want to be able to copy a tab. There are two simple ways of doing this:
 
Method one: mouse
By simply holding down the Ctrl-button on our keyboard while dragging a tab (as if to relocate it) you instead create a copy of the tab where you drop the tab.
 
Method two: keyboard
Start by clicking Ctrl+L to activate the address bar. Then press Alt+Enter. This will copy the current tab to a new tab located at the far left of the list of tabs.