Many people have been using this version of acoustica to convert their DRM files:
http://www.tech-recipes.com/windows_tips858.html
This version is still converting files very well. However...
If you use this version, do not upgrade!
The new version of acoustica has fixed this "bug"
http://www.acoustica.com/mp3-wav-converter/history.htm Version 2.5 build 19- April 14th, 2005
Fixes tag issues with WMA (Track number missing)
Fixes bug converting some small sounds
Fixes issues with Save As dialog when another file exists with the same name.
Fixes bug when ripping CDs and tag info. (Was not using genre and track #)
Fixes bug when converting to WAV and then back. (Tags were not being preserved!)
Fixes bug that allowed some users to convert WMA's with DRM.
Fixes reading of MP3 tags made by Real Networks
In summary, the older version of acoustica noted above still works well. Once you start using it, just do not upgrade it.