Steve,

>I have an mmDropDownList with two way binding. On opening the page, the binding works fine. But when trying to save, using this.Save( myBizObj, dataSet), I receive the error "Specified cast is not valid".
>
>It happens in the call to BindBackPropertyBoundControls().
>
>Stepping into it, it fails at the point where it's looping thru the line which reads:
>
> // Cycle through all Property-bound controls
> foreach (ImmWebBindingSimple control in this.PropertyBoundControls)

Are you binding the combo box to a property of the form or the business object? You shouldn't be hitting this code unless you are. If you accidentally specify an invalid BindingSource or Display/Value member, it may think you're trying to bind to a property of an object instead.

Regards,