Ext.NET: Form fields on RowExpander don't focus as expected

Question

Suppose I have a field defined like this inside a RowExpander :

x.TextArea()
    .Flex(1)
    .MaxHeight(200)
    .Editable(true)
    .MarginSpec("1 1 10 10")
    .Name("comments")
    .FieldLabel("Comments")
    .Width(400)
    .Height(150)
    .GrowMin(400)
    .Grow(true)

This field appears fine but I have problems trying to click on it. The only way I've seen this field gain focus is if I click on the field label rather than the field itself. I notice that this is also a problem with Ext.NET's website . Is there a way to make the actual text area focus-able or is that a limitation of or bug with Ext.NET?

On a related note, I don't think the label itself should be focus-able. How would I make that happen?

UPDATE

After a little more investigation, it appears that the focus is "falling through" to the row of the GridPanel that contains the RowExpander which in turn contains this text area.