The Irish company who hosted this site and my domain was bought last year by a UK company. Apparently the (updated) data on my domain name got lost in the transfer, that's why you saw the ads last week. It took a lengthy e-mail conversation and a phone call to UK to straighten things out. Ugh!
At first I thought that my site had been hijacked, but some investigation by C revealed that it was actually my host that had redirected my domain to some advertising. Double ugh! I briefly considered switching (Ads! Ads on MY site! Yuck, yuck, yuck!!), but decided I can do that if they don't fix it. The UK representative was nice and helpful so I'll probably stay for a while. At least until the next mess-up.