Maps working for some folks, not for others

I just installed a new site after having tested it both locally and on my own site. I have two pages which contain Google maps generated by the WA Pro Maps extension. They have worked perfectly up to now.

I did get a new API key for the current installation, and I and some others can load the maps no problem. Others are getting a pop-up dialog stating that the credentials are for another site. This is odd, since I changed the key in the code. Even my friend in Spain can load the maps, but I've tried it on some of the machines at work and no go, except for my own desktop.

Can someone take a look-see and verify whether the maps are loading? If not, maybe someone could shed some light on what might be wrong.

rockville_map.htm

takoma_park_map.htm

Thanks!