A bug was reported where images appear twice when copy/pasted into the composer window. ChrisBeach initially reported the issue in Chrome on Windows, and later managed to reproduce it in post 2.
I’ve had multiple reports of images appearing twice when copy/pasted into the composer window. Both of the reports are in Chrome on Windows (both v7 and v10).
I’ve not been able to reproduce this myself.
In the most recent report, the resulting raw markup is this:

