i tried to mix down to a file from 3 tracks of 48khz/24bit audio to a stereo 41khz/16bit AIF file, which sounded quiet and very very very clipped, when i set it to export to 48khz/24bit AIF it sounded fine.
using latest metro LX on macintel with 10.4.5.
ta
(thought this may have been off topic where it began - hope that's ok!)