Partial map showing

I’m using the plugin successfully on normal pages within wordpress, e.g.
http://vellafrontera.com/where-to-find-our-wines/
but when I try the A-Z Widget, it goes weird (truncating width of map and not centering on the location).

Could you take a look and let me know what could be causing it?
You can see the problem if you hover over Contact on the main menu of http://vellafrontera.com

http://ww.wp.xz.cn/extend/plugins/google-maps-v3-shortcode/