Thanks for the input Magica. Yes, the white pages are very, very annoying. I don't think I've had any today, but I've had a few log-in pages.
Last night at about 10 or 11 pm NT my Internet started working properly again. This time for good - so far. I got a reply from my ISP this morning. Here's the main part of his message:
"It appears that it was in fact caused by a Distributed Denial of Service (DDoS) attack on a website that is hosted on the Rogers/Sprint network. We connect to the Internet indirectly through Rogers Canada. Here's a posting from the company who was the target of the attack:
Sixapart.com
Sixapart was a company that owns LiveJournal, and was targeted by a DoS attack a few days ago.