Glenn,

>[NullReferenceException: Object reference not set to an instance of an object.]
> OakLeaf.MM.Main.Web.UI.mmWebBindingStrategyList.BindData(ImmWebBindingList mmControl, mmBusinessObject bizObj, Boolean bindBack, mmBusinessStateChangeEventArgs e)

Based on your stack trace it looks like the error is occuring when trying to bind back one of your list boxes. On the web, when you tell a business object to save, it raises a "Saving" event. The UI controls that are listening to that business object bind their values back to the business object and that is where the problem is occurring. To see which listbox is causing the error, you can turn off the binding on each one (set the BindingType to None). I recommend looking at the listboxs' BindingValueSource and BindingValueSourceMember properties to see if they are correct. If you don't see anything wrong there, I recommend setting a breakpoint in mmWebBindingStrategyList.BindData() to see what's happening.

Regards,