I have an iBook 12" 1.33ghz. I was stupid and didn't buy it with more than a 40gb hard drive. I want to upgrade it at a local compusa or microcenter, but they are telling me a 5400rpm (or maybe it was a 5200rpm) hard drive will be fine to run in my ibook. I have looked over the net and found many people saying not to get anything more than a 4700rpm hard drive in an ibook because of heat issues. What do you guys think? anyone?