With previous HomePage-created sites, the HTML name of the page only included a number if it was the second or greater page of that category. For example, the first photo album created was titled PhotoAlbum.html, the second photo album was PhotoAlbum1.html, the next photo album was PhotoAlbum2.html, and so forth.
Since HomePage 3.0, the pages no longer number this way. Instead of counting how many pages of any one template have been created, the numbers now reflect how many pages in total have been created. Thus, if your first page is a photo album, it will be PhotoAlbum1.html. If your next page is an iMovie page, it will be iMovieTheater2.html, even though there was no iMovieTheater1.html.