get_sidebar with name parameter is displaying too many sidebars

I inherited what I thought would be a simple design project: add three widget areas to a home page.

The existing functions.php had register_sidebar arrays for:

'name'=>'Home'
'name'=>'Page Left'
'name'=>'Page Right'

(unnecessary code removed to shorten post)

I added

'name'=>'Video'
'name'=>'Home Page Latest Posts'
'name'=>'Home Page Newsletter'

I then added my first widget area on the home page with:

<?php
	if (dynamic_sidebar('Video')) {
		get_sidebar('Video');
	}
?>

above the existing get_sidebar('Home');

My ‘Video’ widgets show up exactly as expected. What I also get, though, is a second copy of the widgets from the Home sidebar.

Even more peculiar is that this second block of widgets is wrapped in
<div id="sidebar" role="complementary">

A global search though the all the theme php, css, widgets, plugins, page/post content, and even the comments doesn’t find that code.

When I remove the get_sidebar(‘Video’) the second copy of the Home widgets also goes away.

There is no sidebar.php or sidebar-x.php in the theme, and the only other theme in the folder is TwentyTen, which does have a sidebar.php, but it does not contain the offending code.

If I remove the widgets from Home, then a Page List appears, which tells me there is a default theme lurking somewhere, but I don’t have FTP access to the site to verify that.

1. How is an explicit call to a named sidebar retrieving content from another sidebar with a different name?

2. Where is the <div id="sidebar" role="complementary"> coming from?

3. How do I get rid of the duplicate content?

You can view the site at:

http://solarbridge.staging.wpengine.com/

WordPress version is 3.0.4
Plugins are:

• Advanced Most Recent Posts Mod
• All in One Webmaster
• Crony Cronjob Manager
• FormBuilder
• Highlight Search Terms
• KG Archives
• List Subpages
• Newsletter Pro
• NextGEN Gallery
• Recent Posts Embed
• ShareThis
• Video Sidebar Widgets
• Viper’s Video Quicktags
• W3 Total Cache
• Widget Logic
• WordPress Importer
• WP-Crontrol
• WPEngine Snapshot
• WPEngine System