It not working well with the latest version of the bootstrap select.
if you using ng-option like this:
ng-options="c.text for c in timeUnit track by c.value"
This piece of code causing problem.
function refresh(newVal) {
scope.$applyAsync(function () {
if (attrs.ngOptions && /track by/.test(attrs.ngOptions)) element.val(newVal);
element.selectpicker('refresh');
});
}