I've just downloaded the free track 'Oranges and Apples' from Linn in both 24 bit FLAC and 320kbps MP3 formats.
When comparing the FLAC version to the downloaded MP3 version there is a very slight difference in the way they sound. However when I converted the FLAC file into an MP3 myself it sounds identical to the original FLAC file.
When I analyzed the three files using the program 'Audacity' it's clear that the downloaded FLAC and MP3 files have been mastered to sound different from one another. As you can see from these pictures the downloaded MP3 has less dynamic range than the FLAC file. However when you compare The FLAC file to my own MP3 they both look (and sound) identical and they both have the same amount of dynamic range.
This clearly shows that Linn has deliberatly mastered the MP3 version to sound different to the FLAC version by reducing the amount of dynamic range in the MP3 version.
Linn downloaded 24 bit lossless FLAC
http://i1239.photobucket.com/albums/ff512/steve__1979/Linnlossless.jpg
Linn downloaded MP3
http://i1239.photobucket.com/albums/ff512/steve__1979/LinnMP3.jpg
My MP3 converted from the original Linn FLAC file
http://i1239.photobucket.com/albums/ff512/steve__1979/MyMP3.jpg