Glen,

>I have a form that was getting too complex, so I put a tab control (inherited from MM) on it with multiple tabs. At run time I lose the databinding on most of the visual objects. I move the object off of the tab and directly onto the form and the binding works. Move it back onto the tab and it fails.
>Any ideas would be greatly appreciated.

It may be losing its binding information when you're moving it back and forth between the two locations...VS .NET auto-generates the InitializeComponent code that sets the binding properties of all controls.

If a control isn't binding properly, it's one of two things...either it's not getting registered with the business object or it's not responding properly when handling events raised by the business object.

I recommend setting a breakpoint to see what's happening. For a textbox control, you can set a breakpoint in the form's InitializeComponent at the point where a value is stored to the control's BindingSourceMember dialog. When this occurs, the text box registers itself with the form which in turn registers the control as a listener to the specified business object.

If the registration process is occurring properly then try setting a breakpoint in the mmTextBox StateChangeHandler method to see if the event is getting called when it's supposed to.

Regards,