After i go above certain level of volume i get massive squeal and hum in the background. Listening to songs is impossible as bass is cracking and the sound is unnatural. I'm not entirely sure but it actually may be caused by microphone that for some reason is constantly turned on. What i mean by that is that when i speak with my mouth close to mic i can hear my voice coming out from the speakers 0.o. Btw. I realised that "this mac" shows that my cpu is 1,2Ghz insead of 2.4 ( i guess)... How do I know that Power Management is working?