VB Express Beta 2 BindingNavigatorDeleteItem creates unhandled exception

Forgive me if I'm missing something obvious but I'm new to this.
I have a simple database with 2 tables, and a Foreign Key constraint between the parent and child tables, such that changes/deletions are not permitted in the parent table if the child table has related rows. I have a form displaying a DataGridView containing the parent table. This all works fine in that a DataGridView.DataError is raised causing a System.Data.InvalidConstraintException, which I can deal with using an event handler for the DatagridView.DataError.
However, deleting an invalid row by pressing the BindingNavigatorDeleteItem button crashes with the message "InvalidConstraintException was unhandled", but at no point in the code.
Highlighting the row and pressing the 'Delete' key does not do this, it is captured by my DataError event handler.
Is this a bug or am I missing something?
Thanks

[908 byte] By [IGK] at [2008-3-1]
# 1
In the meantime, I replaced the BindingNavigatorDeleteItemButton with my own button, and put the code in to delete the row:

Me.MyDataSet.parentTable.Rows.RemoveAt(Me.parentTableBindingSource.Position)

I can then put in an exception handler to catch the exception. The problem with the default button, is there is no code to put the exception handler.

IGK at 2007-8-21 > top of Msdn Tech,Visual Studio Express Editions,Installing and Registering Visual Studio 2005 Express Editions...