Changing the default file manager -- as it relates to firefox

[Andrew Robinson]

I lean towards KDE style programs when I am using XFCE. I prefer their
UI over gnome applications and really dislike nautilus as a file
manager. (I usually use Krusader as my file manager).

It is quite a pain that nautilus is used by default for many "open
with" dialogs, especially from firefox and thunderbird. How can I
change XFCE to use Krusader or at least Konqueror for the default file
manager (the settings dialog doesn't seem to be able to set the
default manager)

Using xfce-4.2.3.2

-Andrew