nHibernate在一对多上的空列表值

I have an Order mapping with many OrderItems. The mapping correctly saves both the Order and OrderItems to the database when I do a save on just the Order, but when I reload that order, the List of OrderItems that the order contains is filled with null values (for all the othe order items in the table) until it reaches the OrderItem that has the Order's foreign key. So the total count of null order items is the row count of the OrderItems table, (sans the actual order items that are related to the Order). Here's my mappings:I have an Order mapping with many OrderItems. T