When you change a site's skin from Admin > Site Settings, most of the pages on the site change, but not all of them.

DotNetNuke allows you to set skin's on both a Portal and a Page level.  The page whose skin is not changing has been specifically set to use a different skin.

In order to make the skin change, follow these instructions.

1)  Log into your site as admin or host

2) Go to the page that is having the issue.

3)  Under the "Page Functions" at the very top, select "Settings"

4)  Select Advanced Settings > Appearance

5)  Set Page Skin and Page Container to be "<Not Specified>"

6)  Scroll down to the bottom and click "Update"