Originally Posted by 2012Tony2012
Firefox says : Real Memory size 160MB and Virtual Memory size 3.37GB. What is VM and why does it state 3.37GB RAM seeing firefox is only using 160MB real RAM?
Next time, before clearing the memory with that "Free Memory" app, Quit Firefox. And I don't mean just close it, but Quit it. Then reopen and see if the problem persists. If Firefox is behaving badly and leaking memory, then that should clear it. When you were rebooting, you were also Quitting Firefox... So you may have been doing more than you needed to.
If the memory issue goes away when you Quit and reopen Firefox, then it's time to look at what is happening with Firefox. What extensions and add-ons does have it have, etc etc
If the memory issue doesn't go away with the Firefox Quit and reopen cycle, then I suspect the problem is with something else you have installed. What people have been telling you is correct, OS X manages memory very well. You should not have to run an app like Free Memory, if OS X is running properly. This does not mean that your problem does not exist... but if it does exist then there is something unusual happening with OS X, and it may be better to figure that out rather than just treating the symptom. Specifically, what other little apps, add-ons, enhancers, etc have you installed to make OS X run better? It will almost certainly be one of those...