The Image Info link on photo display screen is now working for version 1.4.1.6. I tried 1.4 and same problem but 1.3 is working fine. Without this feature, visitor cannot see the EXIF for the displayed photo. I am wondering what is the latest version when Image Info still working? I hope the problem will be fixed in next new version.

1.4.1.6 is the latest official version but feel free to test the 1.4.2 beta (nightly build) yourself.

Also you are probably referring to the Colorbox popup window. This is not a "standard" but a theme decision. So you don't need to use that as you can also modify whatever theme your are using to display that info directly.

EDIT: If you think this is actually a metadata bug (which a post on your blog seems to do....) you should open a ticket with exact information what you did, what theme used and probably an example image.

How can I know which theme the web page is displaying so that I can include it in the ticket?

You can look at the HTML (page source) at the bottom is all the Zenphoto details. But did you not select the theme originally? Themes are selected from the admin themes tab. The currently selected theme will be indicated there. This will be the theme unless you have selected to configure multiple themes.

Please note that Zenphoto distributes five themes. You can tell if the theme you have active is one of these as there will not be a "delete" button.

You should update this post with the theme you are running. Note that if it is not one of the Zenphoto themes most likely its aurhor is needed to help you.