google maps layer not properly displayed

I am showing a map through a colorbox link and using the OSM Mapnik maps everything works as expected.
But if I use the Google maps layer instead, the map is not fully displayed. I'd say there's a slight displacement too.

You can see an example here . In order to see the map click on the location icon at the right of the title, then change layers to see the difference. Sorry about the long path to check the issue...

Thanks for such a brilliant module.