You can try unchecking the ringtone option in the View >View Options and clicking 'OK.' Then go back in and try checking it again. See if the songs update and show the ringtone symbol next to them. If you still do not see a ringtone icon for a song that should be capable, try right-clicking on the song to see if it will allow you to make a ringtone out of it.
Hope this helps,
Jennifer B.