So it seems lately i've been having some problems with m early 2008 MBP. the fans are spinning (according to iStat) at 2001 RPMs, but when you listen, there's the humming noise from the fan, or hard drive. it is like someone flicking the finger on a piece of paper, but very softly..the fans have also been spinning pretty high just using iChat, and it's sitting on a desk. should i be worried about the noise? or what is it would be the better question..