Weird behavior of the checkbox in HTML5 form

[Manishm1]

I am working with Adobe livecycle designer tool to create HTML 5 forms.  I have a scenario where the setinstance method is used to set the instances for the location description and Transit rows.

Page1.crdcServices.locationRows::calculate - (JavaScript, both)
var locationCount = crdcServices.numOfLocations.rawValue;
if(locationCount > 0){
this.presence = "visible";
this.locations.instanceManager.setInstances(locationCount);
} else {
this.locations.instanceManager.setInstances(1);
//this.presence = "hidden";
}

The chekbox event (click/change) events stops working when the set instances method reduce the higher number of instances to lower number. 
This functionality breaks only in HTML 5.
 When we preview it as a pdf it works well. 
Any input will be highly appreciated. since it looks like something wrong with the events when instances are reduced.