I upgraded my Macbook from 1.25gb RAM to 2gb RAM. The two RAMs are the same size (1gb), same speed same brand same everything. However, when I run Parallels, shut it down, and re start it, my whole Mac OS X became super laggy. It is fine when i shut down and run Parallels for the first time but when i re start it, the whole OS becomes very laggy. When i switch back to using 1.25gb, everything is fine. I am suspecting that it has something to do with how OS X handles memory. Any help on this??