I purchased a Dual Intel Processor 2.4 Ghz RAM MacBook Pro around January or February and recently I've started to come into problems running some Plug Ins with my Pro Tools program. I wanted to upgrade my available RAM to 4GB but after visiting several sites (including apple.com) I've become aware that I can only use 3GB effectively no matter how much more I put in there. I'm heading to Micro Center to buy a 2GB to at least upgrade it to 3 but if it is at all possible then what can I do for more? Also what can I do to stop unnecessary programs from running in my background? How do I know whats a vital process that needs to be open and what is one that I can close safely without interrupting OS x? Just as an FYI I am running Pro Tools LE with an Mbox 2 Pro. Using an external Firewire drive and OS X 10.4.3.