How do you get changes to an entity to show up in a parent entity set that references the record via a navigation property in an ADO.NET Entity OM?

Question

In an ADO.NET Entity Framework object model, I'm running into some trouble with related tables. (Navigation Properties) My backend datastore is a SQL CE database. When I make changes directly to the related table, these changes don't show up through a higher level table ever after calling SaveChanges. My changes are saved perfectly back to the datastore, but when I query a parent table, the child table has stale data.

context.ApplyPropertyChanges("SubTable", SubTableItem);
context.SaveChanges(true);

When querying the data, I use a call similar to the following:

context.MainTable.Include("SubTable");

MainTable has a 1-* relationship with SubTable and SubTable is a navigation property of the MainTable Entity. When I propagate the SubTable changes back to the datastore, is there a way to get the changes to show up in the SubTable field out of the MainTable.

Thanks