Spotify Forum

According to Spotify the mp3-decoder with wine is not good enough.

From http://www.spotify.com/int/help/faq/wine/
"Local Files
Spotify uses the system-supplied MP3 decoder on all platforms, and during our limited testing we found the Wine decoder to be excessively unstable on quite a few MP3 files, including some from our purchase partners. We are therefore blocking codecs with the identifier “WINE-MPEG3″ until the Wine system works satisfactorily."

I managed to get it fixed by following theses steps :

1/ Get the file "l3codecp.acm" (from a google search or from the directory /system32 of a classic windows install)
2/ Copy this file in the folder ~/.cxoffice/Spotify/drive_c/windows/system32
3/ Rename it as winemp3.acm
4/ Add the library in Wine :

• Open the wine configuration tool of your Spotify bottle
• In the library tab, type winemp3.acm on the "new replacement for" field et click on "add".
• Choose yes on the warning window
  5/ Reboot your bottle

It worked for me perfectly, contact me if you need help...