Mario and Gordon,
Thank you both very much for weighing in on this. I, too, suspect that the file is somehow damaged, but it does play correctly on my computer system; however, I will re-download and try Max to convert the file (I normally use XLD).
The Touch is certainly long in the tooth and shy on processing power, but for now I need to live with it. I will post this question to the Squeezebox Community as well to see if anyone has an answer. I have a 24/96 copy of the file and it plays (and sounds) just fine (ChannelClassics is great about providing all rates of a musical selection when purchasing, and keeping them available for downloading any time after purchasing), and in the grand scheme of things this is a pretty minor issue. Just one of those weird, annoying little things that has me baffled 🙂