I've made one or three lately, and I think I'm close to working out how it has happened.
I write my post, "preview" it, then "create" it.
Then I immediately see something (insignificant) that I want to change.
So ... I change it ... and hit "create" again ... and now there are 2 posts.
Can this unfortunate state of affairs be rectified by means that don't involve more intelligent behaviour on my part ?
Update: Perhaps I was being a bit harsh on myself. Having hit "create", the only button then immediately available is an "update" button. It's the hitting of that "immediately available" update button that's creating the duplicate.
That aint right. Do I need to elaborate ? ... I reckon I could even provide a demo.