Old iTunes Plus glitches rear their ugly heads into the iCloud

When I check "Purchased" in the iTunes Store, and look under "Not in my Library", it lists several items that I do in fact have in my library. After I downloaded a couple of these, I noted that:

(a) the songs listed were ones I'd purchased back before iTunes Plus existed, and which I'd upgraded to iTunes Plus;

(b) the new downloads were downgrades to the pre-iTunes Plus versions! (Thank goodness for Time Machine)

Also, there were no fewer than three versions of one song shown ("Then Came You," Dionne Warwick and the Spinners), differing only in that they were listed as being on different albums. This, too, was an old iTunes Plus issue, and the same song continues to show up in "iTunes Plus: Upgrade Now" even though I upgraded it long ago. (OTOH, Ween's "Push Th' Little Daisies" still isn't available for upgrade, but that's a record company issue...isn't it?)