Steps do reproduce the problem
When you are answering some question...
- Click on the
Code Snippet
button or press CTRL+M - Click on the
X
at the corner or press ESC to close the window - Choose
OK
to actually close the window - Repeat steps #1 and #2
- Click
Cancel
and the window will be closed anyway
I tested in Chrome (last version) and Internet Explorer 10. It does not matter whether I am logged in or not.