Applying a new style to a multi-level list resets all the indenting

[retrocool]

Say I have a multi-level list like this:
• Item 1

* Sub Item 2

~ Sub Sub Item 3

If I apply a new style to it, even if that style already has multi-level lists defined in it, all the indents disappear and it looks like this:

• Item 1
• Sub Item 2


• Sub Sub Item 3

This is a problem for me as I have lists with hundreds of items in a document, and I need to restyle about half of them (so I cannot just change the style they are already assigned). If I make a new style with the relevant changes and apply it, all the indenting disappears, and I would have to manually recreate all the indenting.

Any ideas how to overcome this?