macbook pro with Platinum problems

[bluejonhi]

Hello this is my first time posting. I recently purchaced Platinum Orchestra for my macbook pro. I was told by someone at EW that it would work fine as long as I had at least 2 gigs of RAM. I purchaced more RAM and set it all up and am now having all sorts of problems. One problem is that it is taking forwever to load. Two, at the end of a sample it will cut out before the sample is finished or it will make a loud noise at the end of the sample. I am new at all of this and decided to go for the platinum because I wanted the 3 mic positions but now I am scared that I will not be able to use it at all. I am using Kontakt 2, with my EW libraries on a 500 gig OWC Mercury hard drive 400 firewire. I can not afford a desktop so that unfortunatly is out of the question. Did I just set things up incorrectly, do I need another gig of RAM or am I just screwed beyond belief? Any advice would be very appreciated.
Thanks for your help,
bluejonhi