Cannot save layout page in Moss

I am trying to update a layout page in Sharepoint Designer but when I click Save I receive an Access Denied error. I can see that the layout page is created by the system account. I am in the site owners group so I think I should be abl开发者_Go百科e to make modifications to the page.

Any help?

The page could be checked out by the System Account or never had a published version, also, site owners have limited permissions in the site collection (where the page layouts reside)