How to Bring Back The Mysterious Missing Gone Disappeared Ribbon Items in Sitecore
In my Sitecore travels, one day I noticed that the "Publish" button was missing in my Sitecore ribbon. After much humming and hawwing with way too many team members, and diving deep into our core db security permissions, another team member came along and was immediately able to identify the problem. You can actually right click the ribbon and select which buttons to show or not show.
Hope that helps.