Here are the samples from the FLAC files related to this post (http://www.hydrogenaudio.org/forums/index.php?showtopic=89818&view=findpost&p=763779).
The file A1 is a 7 second clip from the FLAC file from UMG. The file A2 is a clip from passionato.com. The file A2 has a clearly audible sort of "flutter". The file A3 is the difference of the two wave forms, amplified by 30 dB. The difference is peculiar. It's spectrum lies almost entirely in the range 350 Hz to 3500 Hz. There is nothing between 3500 Hz and 13,000 Hz. (After that, the spectrum shows a hump of higher frequencies, which I guess are meaningless.)
Another Passionato vs. UMG FLAC comparison related to the thread referenced by mannheim:
[attachment=6631:07___Mor...sionato_.flac]
[attachment=6632:07___Mor...am__UMG_.flac]