MenuItem.Checked = false; not working.

Hi,

As title, I use program code to set MenuItem.Checked = false but the menu item still have the check mark on the left hand side. Refer to the screen capture, I reset the value of all items and in the debug window I confirmed that only 1 item is set to true. But all the items used to be Checked = false still have a mark on the left hand side.

Regards,

Felix