How to hide Jewel Menu's item? (e.g Hide New Task, New Phone...)

Hi,

Does anybody have idea how to remove some menu items in New Activity under Jewel Menu.

Like picture below, I only need to hide selected activities option from the Menu.




I have tried to insert like below to the application ribbon XML, but this will remove the entireNew Activity from Jewel Menu. 

<CustomActions><HideCustomAction HideActionId="CustomHideAction.JewelMenu.NewActivity" Location="Mscrm.Jewel.NewMenu.NewActivity" /></CustomActions>

I also tried to extend the location like  "Mscrm.Jewel.NewMenu.NewActivity.Task" but it prompt me error XML when i import the customization.

Does any1 have this problem also? Please help... tHanks