In case you were wondering, your iPod is not broken: the song segues in Episode 5 really are too loud. At the risk of using too much technical jargon, something went wonky during the editing. We didn't realize how loud the segues were until the episode was online.
So for Episode 6 and then on, we're doublechecking to make sure the volume stays more or less even -- or, at least it won't soar to lethal levels.
See you in a few days, and happy running!
Nik and Dan