Crap...sorry, some of those image links in the last message were wrong
(the first one).
Here they are again:
Non symmetrical looking waveform in Audacity on my "new" PC:
http://www.postimage.org/image.php?v=gx1nuWE9
And it looks the same in the DAW application "Reaper" on my "new" PC:
http://www.postimage.org/image.php?v=aV2iDhY9
So, I loaded this same audio file (the undulating one) into both of
these older pieces of software. Lo and behold - the waveform looks
symmetrical - the way I am "used" to seeing it!
Diamond Cut Audio on my "old" PC:
http://www.postimage.org/image.php?v=Pq2jK5jA
Samplitude on my ancient (but beloved) Amiga:
http://www.postimage.org/image.php?v=gx1nZHK9