Unable To Load .WMA Files

On Slackware 12.1

output of mocp --version
moc 2.4.3 Build: Jul 4 2008 18:57:45
Compiled with: OSS ALSA internet streams

I noticed today that moc won't play my .wma files. I have libvorbis, flac, ffmpeg, and all the other required softwares installed. I'm able to play .wma files with Xine and Audacious, but not with moc :\

I have no ideas how to fix this. Any suggestions would be appreciated, thanks in advance.