Map doesn't recenter in Firefox when using the browser back button

See: http://www.india-custom-tours-blog.com/ggt/

Click on one of the markers in the map, then select a link in the popup. From the resulting page, hit the “back” button on the browser.

In IE10 and Chrome, map recenters itself and all is good.

In Firefox, the map doesn’t recenter. Clicking on some of the markers, the popup is partially obscured.

Is there a way to fix this?

http://wordpress.org/extend/plugins/mappress-google-maps-for-wordpress/