SPItemEventProperties itemupdated beforeproperties is empty

Can't quite get where to use beforeproperties, afterproperties and properties.ListItem? Sometimes is null sometimes is just not you are expecting.
 Here is a neat table with what you should expect where and when in SPItemEventProperties class

Sharepoint List

Event	BeforeProperties	AfterProperties	ListItem
ItemAdding	Null	New  Value	Null
ItemAdded	Null	New Value	New Value
ItemUpdating	Null	Changed Value	Original Value
ItemUpdated	Null	Changed Value	Changed Value
ItemDeleting	Null	Null	Original Value
ItemDeleted	Null	Null	Null

Sharepoint Document Library

Event	BeforeProperties	AfterProperties	ListItem
ItemAdding	Null	Null	Null
ItemAdded	Null	Null	New Value
ItemUpdating	Original Value	Changed Value	Original Value
ItemUpdated	Original Value	Changed Value	Changed Value
ItemDeleting	Null	Null	Original Value
ItemDeleted	Null	Null	Null