MacBook Pro Lion crashes after a progress bar boot Basically my MBP started giving me messages (out of nowhere) about how my Memory was too low and that I needed to shut down a few programs before continuing. In the end I was left with only Finder running, so I decided to restart it. When I did, it simply gave me a Progress bar which loaded to about a tenth, before the computer shut down entirely. I have already tried to reset my PRAM/NVRAM, and booted through CMD + S, which in the end gave me the answer:'Invalid Leaf Record Count 12414 instead of 12416' ... I have also tried the /sbin/fsck -fy protocol which did not do anything. Any suggestions please?

Thanks!
It could be a few different things that are causing this issue.

I would highly recommend taking your computer in to the Genius Bar at your local Apple Store and having them take a look at it. 

http://www.apple.com/retail/geniusbar/

Its free for the appointment and the diagnostic even if you are out of warranty and will probably be the fastest and easiest way to get to the bottom of what is happening with your machine.  

I know its not an instant fix but it will make things a lot easier to have them look at it.