I've found that it's impossible to change the bullet/number style of the default headers (Head 1, Head 2, Head 3). I've tried changing it through the style manager to find that my settings are overridden and the only way I found to change the list style of headers was on a paragraph-by-paragraph basis. Reproducible: Always
Thanks for the report. This is due to the fact than Head1 is an outline style, as opposed to a basic list style. I agree however that the UI should be changed. *** This bug has been marked as a duplicate of bug 305295 ***