Periodically (maybe once a week) I walk into my computer room to hear the fan spooling at full speed. The iStat widget shows it is between 4-5k RPM. Sometimes restarts fix it (have to do multiple) or I reset the PRAM and that seems to fix it every time. It however happens again randomly... I talked to the local apple repair facility and they will take it in and look at it however I will be without my business computer for 3-4 days, which cant happen. Is there anything I can do to resolve this issue or is it purely defective hardware?