It's bizarre, isn't it?

I did have a short chat with my host who said it's the caching that's the problem. Apparently it's not very efficient.

I also received an email from someone who didn't want to put specific technical information about his website in a public forum (I can understand that), but he recommended that I take a serious look at ZBBlock http://www.spambotsecurity.com/zbblock.php -- it did seem to help reduce some load times but certainly not a complete cure. I think with sites like mine with a bit more traffic, you have to be concerned not only about the threat of spammers, but the fact that they are constantly looking for a place with vulnerabilities. ZBBlock puts a stop to that.