I wrote an override of GetParentForm in or derived FormManager class, and I changed part of the method from:

if (ParentForm == null && UIControl.Name == "")
{
	CheckActiveForm = false;
}

to:

if (ParentForm == null)
{
	if (UIControl.Name == "")
	{
		CheckActiveForm = false;
	}
	else if (UIControl.Name == UIControl.GetType().Name)
	{
		CheckActiveForm = false;
	}
}

This fixed the problem. It also introduces a bug/feature where no instance of a control can have the same name as it's class. This is good practice anyway, I guess...

Is this a good work-around, or will this introduce problems that I haven't foreseen?

-Nate