I have a menu item which has a few sub-menu items. I've set one of the sub menu item's DefaultItem to true. I tried setting it to false at run time, but it still looks bold... why is it like this?

if you dont understand, I have something like this

File
----New
---------Blank (.DefaultItem = true)
---------From Tempalate
---------Custom

once the user clicks on any item in the New menu, I try to set the DefaultItem property of all menu items to false, and set the DefaultItem property of the clicked menu to true. But for some it's not making any changes
why is this happening?