Django 1.6 admin .preserve_filters not working with MPTT 0.6 admin.MPTTModelAdmin

Question

All,

I have a django 1.6 admin page and I would like to use MPTT but whenever I use mptt.admin.MPTTModelAdmin, preserve_filters no longer works. If I use the standard django ModelAdmin, then preserve_filters works great. Any ideas why the MPTTModelAdmin breaks preserve_filters?

For Example:

class GroupAdmin(admin.ModelAdmin):
    preserve_filters = True

 # Works GREAT and saves the filter when editing/saving a "Group" object

This does not work.

class GroupAdmin(admin.MPTTModelAdmin):
    preserve_filters = True

Does not preserve any list_filter choices after saving/editing a "Group" object.

Thanks for any and all help.