Aranjuez.mp3 - I give you this 1.4 mb mp3, which you can put in MediaCoder, enable Auto Gain in Audio tab and convert it to some other format. The bug I'm talking about is that delayed volume boost with a click at the beginning of the output track.
Now, do you hear that click at the end of my mp3? Well, it's there, because the source WAV file was produced by Adobe Audition. I don't know why MPlayer reacts in such way. It also refuses to work with OGG's produced by Adobe Audition (example: Aranjuez.ogg. Oh, just tried Winamp Input Plugins - it worked... But then why would MPlayer not understand a perfectly working OGG file all of a sudden?
WAV, saved in Adobe Audition, check it out: Biont.wav. Try converting to OGG or MP3 - it will give you click at the end. Try converting to FLAC - no click! X-Files!