This has happened to me a copy of times so I will try to explain my steps. There is actually two things that have gone wrong with adding labels. In the first situation, I am editing a release. I find a label that I would like to add and select but then realize it's the wrong one and change it. When the release is updated, both labels get added. Similarly, if I add a label and then decide not to add it at all and delete it, it will not display on the edit summary page, but still gets added. I was going to try to reproduce on the test server but is says RC2. Is this it the same as production?