Thanks Till, your quick responses are always appreciated. And also, I'm glad you had me look at that (tremendously verbose) logfile...there's a lot of clues to how stuff is being done in there.
I've posted the whole log here: http://pastebin.com/m21303c6d
The relevant lines are about 165-275. There are no errors, but several warnings of this type: "WARNING: could not . /etc/apache2/envvars && httpd -t &> /dev/null" and a few others.
Some time later I did delete and recreate another site without a problem. The only difference in procedure was that I emptied the recycle bin prior to recreating it. Anyway, thanks again for your help.