Thanks, Shane. That doesn't help though. I still get the exception. It does
work if I set the text box to " " (one space) but that's not at all what I
want.

The exception is happening before I get to the EndCurrentEdit method
call...before the click event handler is called, in fact. It must be burried
somewhere in the binding manager. Its as if the binding manager is looking
at my text box, seeing that I didn't enter anything, and trying to set the
bound column to null even though the column doesn't allow nulls.

I hope I'm missing something real obvious :)

--Doug