I have a Zune 80GB and the Zune Software won't import my music?

I have the Zune set to retrieve the music from the correct folder because it imported some of the files. I tried to drag them over and it said that they were the wrong media type so I right clicked and clicked on its properties and it is the same file type as the other music that I imported, Windows Media Audio file (.WMA) I am getting REALLY frustrated! I love my Zune but the software is really starting to tick me off. Does anyone know how to solve this problem?