Nested DIV becomes unnested

I have a really weird issue with a master page file that I have been working on.  I have searched the web for a solution, but have not found anything.  I have been building web pages/sites for quite some time and have never seen anything like this.  In the master page file I have:

<div id="Page">
  <div id="Page">
    <div id="pageHeader">**some content**</div>
    <div id="pageContent">**aspx content place holder**</div>
    <div id="pageFooter">**some content</div>
  </div>
</div>

Select allOpen in new window

** I know that I have to div elements with an ID of "Page", but it doesn't/shouldn't affect page layout, and I don't use them for reference via VB.Net or Javascript coding.

When I view the page in design view or split view, everything looks fine.  And even on the website, any pages that use this master page work fine except for one page.  This one page, for reasons I can't even begin to imagine, separates out the pageFooter div from the parent (second) <div id="page">.

Is there anyone that can explain to me how this can happen?  Is there some server-side code or javascript that can actually move a div element out of parent element before/after the page is built?  I have tried deleting all temporary internet files, searching through javascript includes for anything referencing the pagefooter.  I just can't seem to figure out how or why this is happening.

Any thoughts or solutions would be GREATLY appreciated!