manual update show multiple update notification(Jucheck) if clicked 3-4 times on update now button. It is working fine as expected with previous promoted build 13.
How to reproduce

1.) Install JRE 6u10 pit b26

2.) Set the UpdateServletURL in the registry to a valid XML file

3.) Open the JCP and got update tab

4.) Click "Update Now" button 4-5 times

Expected behaviour:
It should only update notfication one not multiple times

Actual Behaviour:
It open multiple update notification (jucheck) windows. This should be only singleton.