Thanks, Wige!
With your explanation in hand, I'll go back and give it another go. Just wanted to make sure it didn't matter whether it's an .html page or any other file extension.
And your comment about .pdf files is a good one. Ideally, I'd like all of the .doc and .pdf files on this site to be actual .html pages, but that's a lot of work. When it's volunteer work, it has to be done bit by bit, so I can devote my time to making a living.
Cheers,