I know this problem is ancient, but I can't seem to find a clear instruction for it.
The gist of the problem is the Google Map wouldn't load completely (partly shown) when it's loaded on a hidden (display:none) divs, e.g. jQuery tabs, etc.
API V3 wouldn't accept checkResize() any more, the 'left:-1000px' is not an elegant solution.
I've heard delaying constructing the map, and reload the map when click the tabs, but please help me on the exact codes.