when I open the files, its makes me a new frame page with the home page.

the WEBdocs plugin has options as to what it uses to display the document. These will have a great bearing on the behavior. Unfortunately you have not told us the configuration of WEBdocs nor what kind of document you are trying to show.

In general though, WEBdocs relies on an iFrame to display the output of whatever is configured to handle the document. That iFrame should be within your "image" page. So again, maybe there is a theme issue, but we do not know what theme (or even what version of zenphoto) you are using.

-sbillard