I was putting together a project to demonstrate Gantt Charts. Along the way I hit a snag, so I deleted the project. I then created a new project using the original name, but it wouldn't let me add the Issue Tracker service, telling me:
"Project is not unique. An entity with the same properties already exists. Edit one or more properties and try again."
I found that by changing the key, I could create a new project. However, the old key persists: when I create a new Issue and open the dropdown to assign the project, I can see the original key from the deleted project and the new key from the current project. This is not desirable, as people may choose the redundant key.