I have an 80gb classic i purchased recently and am having volume issues. My MP3 files are played at a much lower volume than aac encoded files and are inconsistent relative to each other. I have tried sound check and it makes no difference. This problem occurs only on the classic not on my shuffle, in itunes on mac or pc or in foobar on pc. what can i do to fix this, and why would it occur only on my ipod not on my computer or shuffle?