my white 13' macbook is having real issues with many different usb devices and with audio quality, also random crashing and glitchy cursour and other tedious things. i'm quite certain its not software troubles and its not the ram ether. i've tried just about every fix for these sort of symptoms to no effect... considering all this, would i be right to conclude that its a logic board problem? i just need to know before i order a new one and open up this bad boy...