This is getting rather embarrassing. It turns out that my whole problem was that the Mail::CheckUser package that I was using to check submitted email addresses, always takes several minutes to return a result on the new (FreeBSD6) system, while it "often" returns a result in a few seconds on the old (FreeBSD4) system. So of course the response to the form submission took several minutes.
I will pursue this difference with my ISP and the author of the package. Sorry to have bothered the list about such a thing... Craig MacKenna Los Gatos, CA
