WMA (Windows Media Audio) is a proprietary audio format owned by M$ and oftentimes don't play well with others. In fact, Audacity will not import .wma files (unless that's changed in version 2.0). Therefore, it's necessary to convert the file format to .mp3, .wav or etc.

I use this freebie: http://www.dvdvideosoft.com/free-dvd-video-software.htm

A caution - it wants install another toolbar so read during installation. It has a drag-n-drop GUI which makes conversions simple.