So I got a Pearl 8100C, loaded a media card and got it formatted. Using the media manager I was able to copy a song and see it in the media manager window. I can see that some memory has been used on the phone but when I nav to the music file I can't see anything. Does it matter that it's a WMA file?
Yes... must be mp3 files. Be sure you format the media card on your Blackberry. It's easy to format the card incorrectly on a PC or Mac. Once you format the card using the Blackberry, you should have a directory structure that looks like:
BlackBerry
|_ Music
|_ Video
|_ Photos
|_ Ringtone
Put your mp3 music files in the Music folder. Make sure your mp3 ringtones go into the Ringtone folder. If you put them in the Music folder, they will show up in your Media playlist.