webform example module disable causes a customised webform deleted

bascially I duplicated a example webform for me to start with, I did a bit of customisation on this duplicated webform. However when I finished my own form population which is duplicated webform from example form, I wish to disable the webform example module. It actually removed my customized webform.

I was thinking might be because the category all named as same, but this time I gave a different category for my new webform. it seems still try to remove the form.

Please see the screen shot, I duplicated a example form called "hello world".

I am not sure it's a bug, however It might be better give me a opt-out option not disable a duplicated webform.

I totally thought duplicate means "clone" in view. Once you clone the view, I can do anything with it.