Forms Data Controls :: Excluding Subcontrols Of A FormView From 2-way Databinding?

So we use formviews all over the place that recently we've started putting user controls inside that have databinding controls inside them. In this instance it's a grid so

<formview>
<edititemtemplate>
<dynamiccontrol DataField="name" />
<customGrid DataField="addresses">
<columns>
<dynamiccontrol DataField="city" />
</columns>
</customGrid>
</edititemtemplate>
</formview>

That's the basic sitch. We have the customGrid, a usercontrol, bind to a collection on the main DataItem, and it contains dynamiccontrols (DD4) in its column templates so stuff in the cells displays right. (in reality, the customGrid is inside a dynamiccontrol like all the other fields here and is loaded based on ui hints, I've just stuck it in the pseudo-markup here for illustration). This works a charm, up until you try and update the formview. At that point, the FormView grabs all the keys from all the dynamiccontrols in its edititemtemplate, including keys and values from dynamiccontrols insde the customGrid control. Obviously this doesn't work as those are for an "address" object or something, and the formview is bound to a "person" object. What i desperately need is a way, inside customGrid, to stop FormView from getting out all the dynamiccontrol keys and values inside it. Overriding DataBindChildren doesn't work, nor DataBind. I don't know at what point or how the FormView queries its instantiated template for all the 2-way databinding controls it has inside it, but if I could get at that maybe I could figure something out. Or else, if I could make the customGrid stop sending back all the values inside it.

I tried overriding the formview's OnItemUpdating but that only so much; I can remove entries from the e.NewValues collection if they don't exist on the DataItem, but that doesn't if your custom sub control is binding items with fields of the same name as your main dataitem. There must be a way to abort this 2 way databinding in the custom control.