I have been trying to work out some strange behaviour for a while now. I haven't been able to figure out what is causing it to happen. Sometimes when I am editing a story or page the screen would change. It only happened now and again. Anyway... I have just created a new poll and I realised that when I am using Firefox, if I edit a poll and highlight one of the answers with the mouse the screen changes to the permissions screen. Not quite sure what is happening there. I use Chrome mainly now so it's not an issue, but it might be for others who use Firefox.