If you bugged it or are going to...
Is the fix working on this file for example?
http://www.gutenberg.org/dirs/etext05/shsof1601.mp3
it reports different lengths by about 5 seconds (low bitrate file).
iTunes, the finder preview in column view, and get info > more info (disclosed) calculate the same erroneous time.
Worse, if you advance the start time a few seconds in iTunes it plays fine, but if you burn it the file starts at a different place further back (crops). This makes it almost useless.
I have no idea why the finder defaults to the iTunes calculation method, but it seems like there are two mp3 codecs installed. One as part of quicktime (intermediate? or packaged in the app) and the other part of iTunes...and the iTunes one is erroneous?
My guess... it's not the app, but the component used in playback. The Finder has it wrong as well (at least on my system with that file).