Google maps on that page is working fine for me in IE9, not sure about other versions. To get a good idea of how the site is functioning in other browsers - use this tool:
It only allows you one submission per day I believe without signing up for the service, but it is definitely helpful in situations like these.
As far as not centering in the map, are you referring to the white box with the address listed? This is most likely due to the size of the area you're giving to display the actual map. The map pin centers for me within the space.
Last edited by kelisaid; 12-18-2012 at 08:22 PM..