My iMac (2008, 24" cheap version) sometimes beeps during startup (not always). It beeps 2 times before a pause, and then 3 beeps, pause, 3 beeps, pause, etc. etc. I've found out that this means that it has "no good banks". I have a suspicion that this is also the cause for my random gray screens of death. The problem is, i have no idea what a "bank" is. It's probably something everyone knows but me . So, does anyone know what it is? Thanks in advance.