PS - There is also a bug with "Global Attributes"
If you setup say 3 global attributes, it only allows you to add the first one you captured/created to a variable product. If you add the 1st one it's fine. But when you click the "add" button to add a second one, nothing happens - no errors, etc, it's just a dead click. You can however add a custom attribute as a second option in addition to the first global attribute. Think it may be a bug.