Yes, I think I spoke too soon. I discovered the same "changed" effect soon
after I posted my previous reply. Now I'm stumped.
To make matters worse, when you update the website, sometimes it seems the
file dates change to today's date, so it looks like your remote site is more
current than your local site. This makes the "Use source file timestamps..."
option less useful than I thought. This too, however, seems inconsistent;
some files change, others don't.
I think there's just something basically wrong with how FP does the
comparisons. At first I thought maybe the HTML optimizations were causing
this because the page on the remote site isn't the same as the page on the
local site, but I'm getting this same problem with binary files like JPG
images, files that have identical data and identical timestamps.