Q:
When I drag a bookmark from Notebook (Millennium) into a symbol it will not create a attachment is this is a bug ??
A:
You cannot directly drag bookmarks from Notebook into Diagram! as attachments, but you can drag bookmarks into the filesystem (e.g. into your home directory) and then drag them into Diagram! from there. The folks at Millennium said it has to do with the drag service that Notebook uses, and it may change in a later version.