No matter which link I click on, your content width and header images all appear to be the same size.
The only page which is different is the “Gallery” page, and that’s because you’ve chosen a one-column layout.
Try refreshing your browser cache: CTRL +F5. If that doesn’t resolve the issue, please post links to the specific pages in question.
Your background image is arresting. You might want to set it to “fixed” rather than “scroll” however. You might like that better.