I figured it out. I needed to do the open xml call with just root...

FROM OPENXML (@idoc, '/root, 2) WITH (answer  varchar(100))

>

>declare @idoc int
>declare @answers varchar(100)
>
>set @answers = '<root><answer>123x4x5x6x789</answer><answer>xxx xxxx xxxx xx x xx</answer></root>'
>
>EXECUTE sp_xml_preparedocument @idoc OUTPUT, @answers
>
>select *
>FROM OPENXML (@idoc, '/root/answer', 2) WITH (answer  varchar(100))
>

>
>Ive done this a few times now and I dont understand why its not working. I keep getting two null rows, instead of the values. Its probably something stupid that I cant see.