I did know that. But evidently the people who created the manual IE import did not account for it, because it never worked in IE6, IE7 and now IE8.
I also saw for the bookmarks that would import successfully into IE, they were sorted by name, just like in a file folder view. Which never matched the source.
And now I notice when xMarks syncs boomarks, the bookmarks maintain the sort order in each folder from their source, and do not default to the sort by name. Very nice.