I have two collection classes Customers and Orders that both implement ibinding list that are a collection of Customer and Order objects respectively. Individually they bind just fine to the datagrid but if i want to make orders a child of customers in the grid by adding a Orders property to customers a get a object doesn't match target error or something like that. After some research it appears the problem is that the grid is expecting the child to be of a Customers type. Any suggestions on how to make this happen??