Originally Posted by Netcat
This is the answer. Create a folder on the root of your SD card called "Music" and put all your music in there. Also create folders for "Movies", "Pictures", and "Ringtones" if they are not there already. Make sure folders are spelled exactly as I wrote. Then your phone will also recognize your movies, pics, and ringtones that you store on your SD card.
This may be an answer but it's not the answer.
I have my music in a folder called syncr (put there by iSyncr) on my external SD card but all my music players find my music no problem.