combobox dropdown menu is not closing in IE

I am using smartgwt3.0 version and internet Explorer 10 version.

I have created sample project in that added combobox to vlayout and added to mainpanel.

Code:

VLayout vl=new VLayout();
vl.setSize("90%", "90%");

DynamicForm dF=new DynamicForm();

LinkedHashMap<String, String> listMap=new LinkedHashMap<String, String>();
listMap.put("1", "cocacola");
listMap.put("2", "pepsi");
listMap.put("3", "maaza");
listMap.put("4", "fruti");
listMap.put("5", "thumsup");
listMap.put("6", "sprit");
listMap.put("7", "mirzinda");

final ComboBoxItem nameField = new ComboBoxItem();
nameField.setValueMap(listMap);
nameField.setTitle("Product");

dF.setFields(nameField);
vl.addChild(dF);
vl.redraw();

RootPanel.get("nameFieldContainer").add(vl);


when i opened dropdown menu for combo box and moved from current browser to another Application and come back then dropdown is closing automatically mozilla and chrome but it is not closing in IE10.