Hi, Jeremy.
I believe I owe you a 'thank you' for much (much!) more than answering my question. As a former programmer myself, I see the genious in what you have created. I wish I was more up to date in my programming skills (languages, really), because I have this urge to "sculpt" TW to suit my own tastes. ;-)
Back to my original question (not auto- or manually saving), I have tried this particular TW file on several computers, and on several versions of FF and Chrome. Using my residual programming knowledge, I downloaded "empty.htm" and made a simple edit to the GettingStarted tiddler, then manually saved it. Then I compared "empty.htm" to the backup file and found that there are 9 added lines after line number 524. Other than that, no differences, but my changes are not reflected when I reload the file.
So there is really some strange stuff going on here. Could you suggest anything that would allow me to troubleshoot my problem? (I can trace through code a little bit, still.)
Again, thank you on all counts, large and small.
Rob