Hi,

You could try and override HookParentSave() on the child business object and see if it gets called when a save is done on the parent business object. If it does fire then you at least know that the child business object is registered properly with the parent.

Also, have you set the AutoSaveOnParentSaved property on the child business object? (from the MM .NET Developer's Guide) :

If the AutoSaveOnParentSaved property is set to true (the default is false), when a parent business object's SaveDataSet method is executed, it automatically calls the child business object's SaveDataSet method with no parameters.
If you want to call a different overload of SaveDataSet (or do something completely different), you can set the AutoSaveOnParentSaved property to false, and then place code in the child business object's HookParentSaved method to call it manually.

Hope this is of any help whatsoever

Andrew