Marker Clusterer, not zooming in when clicked

I'm using Marker Clusterer with all the default settings, on a map also using just default settings. The ma开发者_开发知识库rker clusters display fine, but unlike the example in the documentation, the map does not zoom in when a cluster is clicked. The map only centers on the click on cluster but does not zoom!

Has anyone else had this problem before?

Dreendle: the default zoomOnClick setting is true so that clicking a Cluster should zoom in. Are you sure you have not set zoomOnClick to false?

There are no script errors?

That setting was true thank you davidhund. I replaced the code with a different version, and the problem has vanished.