When the first child of an ordered or unordered list is a floated element, Opera "loses" that list element's bullet/number.
Unordered list item, with non-floated image
Unordered list item, with right floated image
Unordered list item, with left floated image
Ordered list item, with non-floated image
Ordered list item, with right floated image
Ordered list item, with left floated image