Q: 4th gen iPod not showing music purchases

I have recently purchased some music on my mac (book, 2008, running 10.6.8... because that is the most it can...) through the itunes store.

As soon as it downloaded, it rang up my ipad (2), ipod (touch, 4th gen, running 6.1.6, also because that is the newest it can handle...) if i wanted to download it onto those devices. I downloaded it to my ipad, adjusted the settings so it would always do so from now on, and instantly had access to it to listen.

I was hoping for the same to happen on my ipod, since i use it exclusively to have access to music in my car, and went through the same authorization process in settings. But when I tried to look up my purchases, it had absolutely nothing in there. I am wondering if the difference between the oler and newer OS would make my music purchases unavailable this way, or if something else might be the issue... I have all purchases throught itunes enabled to download as available, and am really baffled as to why they should be inaccessible since I was given the option specifically to do that through the settings.

I would try to sync manually, but the newer laptop (running the most current OS) that has all my playlists and sync info is currently two states away with my husband, and out of my reach for a while.

As much I try to skirt around not being able to have the newest OSs on my older, but still perfectly well functioning devices, my annoyance grows by the day at isues like these. Hoping that there is a solution to this, rather than another disappointing fiasco repaying my loyalty for these wonderful products...