When I type a carriage-return in a comment adobe.com seems to eat them.
At first I see the blank lines and then...they're gone.
Therefore, I tried shift-carriage-return and the same thing happened!!
NB: when I say "carriage-return" I mean that I hit the key on my keyboard that's labelled: "Enter."
Here are two screen shots--that show, "now you see them, now you don't."
Now you see them:
Now you don't: