UI of Checkbox and radio button not refreshed once having a label for it

UI of Checkbox and radio button not refreshed once having a label for it

Hi,
 
I would like to report an issue. I am using JQM 1.2.0.
 
I have a checkbox
<input type="checkbox" name="neednow" id="neednow"/>
 
And a jquery to update its value
$("#neednow").prop("checked", true);
 
It is working fine. But once I add a "Label" to it, I can still update its value but UI not refreshed anymore.
<label for="neednow">With label</label>
 
Below is my test bed. The one without label works while the one with label doen't.
 
Please help!
 
Regards,
Michael Leung