The tempo is just a beat or so slower.
I'm wasn't asking about "tempo," because that can be influenced by perception. So you actually used a separate "stopwatch" to independently TIME the playing of the exact same song file on your computer, using iTunes, and on the iPod shuffle. And they were noticeably different? How long was the test song, and what was the difference in playing time?
Also I never indicated that anyone would intentionally make a digital music file play slower (though there are apps that can do this - Google it!)
I know there is software to do this, and that's my point. What I'm saying is that to intentionally make it happen, it takes special software and processing (those custom apps). It can't happen accidentally, because it is a digital device playing a digital file.
I've seen other people asking the same question online but like I said, no answers.
Apple sells tens of millions of iPods every year. There are bound to be hundreds of reports of every kind... (whether true or not).
BUT, if you say you timed playing the song with a stopwatch (using iTunes on computer and using iPod shuffle) and they are noticeably different, I will believe you.
(Pick a test song that has a definite end point, not one that fades out, so you can easily tell were the "end" is on both the iTunes playback and shuffle playback.)