Google maps over https

We are using Google Maps over https using a free maps API key. The Google Maps API FAQ says:

The Google Maps JavaScript API and Google Static Maps API can be
accessed over a secure (https) connection by Google Maps API Premier
customers. If the Google Maps APIs are used with a free Maps API key
on a secure site, the browser may warn the user about non-secure
objects on the screen.

My understanding of the above is that the API will work anyway, but users might get a security warning. For us, however, the map will not display at all, rendering the page completely unusable.

Does anybody know if Google is blocking use of the maps API over https with free maps API keys?

Google maps over https