I agree. Generally, open ended questions give you a pretty good idea of a candidate's aptitudes. I had a guy come to interview who'd supposedly got a CS degree with first-class honours from a fairly well-ranked British uni. He couldn't tell me what functional programming was, which I thought was pretty peculiar.

I tried to call the uni to verify his degree but they wouldn't confirm it without consent (Data Protection Act), and I wasn't going to employ him (for several reasons), so I didn't take it any further.