Just a shot in the dark but did you check your music file to see if it was in there? For some reason it just doesn't seem to be recognizing the attachment when you are clicking on it.
I don't know if you have it or not but you might want to consider getting ringdroid from the market. It allows you to create, save and send your own ringtones from any music you put on the droid.
I don't know if you have it or not but you might want to consider getting ringdroid from the market. It allows you to create, save and send your own ringtones from any music you put on the droid.