Dojo Dijit.Form.isValid() when adding fields by DOM Manipulation

I have a dijit.Form element on my page with two fields, name and comments where have just a require=true. Comments don't have validation rules. If i submit the form and check if it is valid it works.

My problem occurs when i add fields name="columns" with DOM Manipulation. It validate when i'm typing, it shows that This field is required, but 开发者_开发知识库when i got my dijit.Form.isValid() it says that don't have errors, but it have, and it is showing me.

What is happening? Why don't validate when i submit it and use the isValid()?

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You must call form.connectChildren if you add widgets to the form after startup.

See http://dojotoolkit.org/api/1.6/dijit/form/Form/connectChildren