Google Maps shortcode doesn't work?

I found this Support article for inserting a Google Map:

http://en.support.wordpress.com/google-maps/#comment-114341

After following the steps, no short code is generated from inserting the iframe code into the Visual editor:

http://www.jenniejane.com/google-map/

I can insert the code in the HTML editor and that works, until you click the Visual tab. Then the code gets completely removed.

I tried created the short code myself, and that doesn’t display anything either:
http://www.jenniejane.com/google-map-2/

Is there a step I’m missing here?