Based on the feedback from another post (http://forum.strataframe.net/FindPost13906.aspx) I was attempting to use OnValidate to update the data source. However, when I set this for a custom control I made, the set property never got fired (the data source was never updated). I implemented a property change event, but I'm thinking I must need a validate event also. What do I need to implement on this control to get OnValidate to work?

One other thing.  If you are inherited a control that already has the OnValidated method, then just call it within your control when you want the control to validate and the binding should follow suit.

I'll look into this. This is a sub classes TextControl, by implementing IBusinessBindable. I'll have to see if it has/raises the Validating event. It should be fun if it doesn't