Instead of rolling back Windows Media Player to a previous version you can try a virtual machine (either VMWare or Microsoft Virtual PC). Install Windows XP (assuming you have your Windows XP install/upgrade disc) on it and run the beta version of WMP 11 if your purchase requires it. If not you may try to use WMP 10 and remove DRM from within the Virtual PC and simply transfer the DRM-free files to your Windows XP/Vista music folder.

Until there is an update to FairUse4WM (if there will be any) to combat the new IBX this is the way I recommend if you use Windows Vista only or updated WMP to the version higher than 11.0.5705.5043.

And NEVER UPGRADE your WMP. If your DRM-licensed media files require an upgrade to WMP 11 use WMP 11 beta 2 or WMP11 beta 3!

And don't forget to re-inividualize WMP through the Microsoft's web-site after installing WMP or rolling it back.

Many thanx to all doom9 members for the contributions