I'll probably put a patch together for this, but the url to load the maps for enterprise and premier customers has an extra parameter on it.

The url looks like:
<script src="http://maps.google.com/maps?oe=utf-8&file=api&v=2&key=myKeyString&client=ClientName" type="text/javascript"></script>

I think it's as straightforwards as adding a ClientName property to the control, so I'll give it a go.