I think I've found the problem. I replaced your Header.asp and Footer.asp files by using my web page template file. The template file is a complete HTML file but contains no content- it contains all opening and closing tags (<html>, <head>, <body>, etc.) and I simply split it where the content is supposed to be.
After doing a page preview, I saw that it now has two of each of these tags.
I'm amost positive this is the issue, but it's kind of late here in California, so I'll work on it tomorrow.
Thanks,
johnk