Note for @manton - no action needed.

Not yet managed to get to a repeatable case to create a ticket, but it happens a lot. Upload an image - use it - all works fine.

Later when in the upload library spot that there are two copies of the image. (But which one is the post using? So you leave them both.)

I will narrow the exact behaviour that causes this before reporting it. In the meantime. anyone else seeing this behaviour?