What IBX version do you have? Is it supported by mirakagi? If not, have you tried to downgrade your WMP?
Have you tried alternative way of removing DRM on Vista like
- installing WMP 10 on Windows Vista,
- using the latest versions of drmdbg, freeme, drm2wmv
- installing Windows XP onto virtual machine
???
If you don't wanna spend your time making fu4wm to work, you can always use lossy
DRM removal software like
Soundtaxi,
Tunebite,...