I have ML installed. And some times I get the color wheel circle popping up quite frequently. I'm thinking it needs more memory. So I was wondering how do I know which one to buy? And does it void the Apple care I have if I open the case? I was looking at this one: http://www.amazon.com/Corsair-1333m...M2A1333C9/dp/B002YUF8ZG/ref=cm_srch_res_rtr_5 Mid 2010 MBP.