This is a good plugin, for the most part, but the Google Maps integration is buggy.
The plugin authors' site alludes to this when they say "Sometimes, people have difficulties with the balloon looking right on their screen."
That's putting it mildly.
When the map loads, it centers on the point for the location, but it should be offset to allow for the info window to display. The info window is always out of the frame, requiring the user to drag the map into proper position.