I have several zenphoto sites attached to my main website blog. All but one are functioning fine. But on one the upload tab is missing. I am the admin on the site with all permissions granted, yet there is no UPLOAD tab. How can I get that back? I have had it in the past. It's just gone missing.

Upload handers are all plugins, so most likely none are enabled. If you wanted to use only the jQuery one it might be the case that the site does not meet the minimum requirements for the plugin.