My sister in college is thinking about getting an 14" iBook with the 32mb ATI Mobility Radeon 9550 video card.... Her current Dell notebook has a 32mb XGI Volari XP5 video card. Is the ATI mobility radeon better than the XGI volari xp5? Right now she's experiencing lag with 1.25gb of ram on her dell. The screen lags when scrolling really fast (which is probably due to the video card) Will the IBook have this problem? Thanks for all help! also, is the ibook very good at multitasking and running a lot of programs at once?