After installing 2.57 The length for a set of files is wrong and different from the real duration and the duration show by Windows Media Player and by Windows explorer. I'm not sure if this problem was present also in the previous versions.
An example is available from https://dl.dropboxusercontent.com/u/2571325/b.mp3
Its duration is 5:13 but in Mp3Tag it is show as 13:34 This file seems correct using various MP3 validation programs.
Machine is Win7 64bits.
Thanks for looking!