Not quite sure why the 4th quarter sounds do not always work. I've found that the 4th quarter sounds only play on my PS3 when the 3rd quarter ends without playing a custom stadium sound.
For instance, if it is the end of the third quarter, and my "defensive stop on 3rd down" stadium sound is currently playing, then the 4th quarter sound will not play. However, if the 3rd quarter ends and it is not an instance where one of my customs sounds is currently playing, then the 4th quarter sound works.