I just ran into a problem on my wife's iMac. If I play a song in Quicktime, everything sounds fine like it always did. The same song in iTunes, however, is far too loud, overdriven and boomy, even on the iMac's lowest volume level. Strange enough, this only happens when I turn off Soundcheck, but as far as I know, it never had been turned on before. (Soundcheck is the option that auto-adjusts the volume during playback, right? Stupid localized iTunes preferences... ). The songs I tested have no special volume adjustment inside them, nor does iTunes use any EQ settings.