I tried this...

oAddress.City = "Initial value";
this.textBox1.DataBindings.Add("Text",oAddress.City,"");

And it didn't error out...and when the textbox loaded, the value in the textbox was "initial value"...but after I entered something into the textbox, the value of the property didn't change.

Seems that anything I try for that 3rd parameter causes it to blow up.

Yeah, I agree, I'm sure it can be done, but I think I'm going to learn something here as well, because I don't think I've ever tried it.

Kevin