hello all-

i have a 1.67g powerbook and am recently experiencing problems with what i can only guess is the fan. whenever i do something taxing that is usually related to, but not limited to, editing video, my computer starts making a grinding noise. it comes from the top left corner. i have read about many people's experiences with hard drive failure, and hope that is not the issue. the reason im guessing it the fan, is that the noise slowly slows down and eventually stops when i quit such applications as final cut pro. when the noise is happening, my cpu top temperature is 143F, and bottom is 125F, if that means anything. those figures are according to istat pro.

any help or ideas would be greatly appreciated.