I think my problem is only one of Frankie's; that is, I think he has a combination of several problems including one that's the same as mine. That "shared" problem is the HTML Editor not rendering a page in split-screen mode in the same way that IE and Firefox render it.
My pages are admittedly very complex (I won't take credit for that; I inherited a lot of machine-generated HTML), but IE and Firefox display them very quickly and very nicely. HTML Editor seems to get confused about where things belong on the page and even what size the characters should be. Feel free to borrow any pages you find at
http://www.allenareapatriots.org to demonstrate the problem.
Incidentally, I've noticed another anomaly that may be related to this problem: when opening a page for the first time, HTML Editor frequently inserts a question mark before the HTML code. If that question mark is allowed to remain, IE and Firefox display the page but make a mess of it. Simply removing that question mark straightens them out. Could there be something internal (that doesn't show up on the editor window) along these lines?