Measure sigma drop-downs not working

After much fiddling around, I discovered that a report must be configured upon page loading, or the sigma drop-down arrows are non-functional.
Here is the scenario you can probably duplicate: index.html page loads the component bare.
var pivot = $("#pivotContainer").flexmonster({
                toolbar: true,  
                height: 800,
                licenseKey: "our license key"
});
Then we have a custom page element that calls flexmonster.load() to pull in the correct .json file via http.
The various reports load and function properly except that the sigma drop-downs on the measures do nothing (there is no drop-down action).
If a report is configured in the initial component initialization, then subsequent loading of the other reports all have functional sigma drop-downs. So, for some reason, if a report is not configured upon component initialization, some thing does not happen under the hood that affects all subsequent report loads be they .json files or querying the icCube xmla server.