You can’t add sub menuitems to a Context Menu Item Programatically for more than one time.

If you try to add first sub menu item it will add up into the list then again if you try to add then the sub menu items wont be displayed,

but if you debug it you will find the Submenu Items will still there .

This is Bug in .NET to over come this problem , toggle the visiblity of the added menuitem submenuitem1.visible=false; submenuitem1.visible=true;