Ditto -- all sweat will taste salty -- and, it's hardly something to base a diagnosis (or lack of diagnosis) on.
People can have normal and/or below normal sweat test numbers and still have CF, so in that case not tasting salty will not tell you anything. On the other hand if someone is overwhelmingly salty, and you see the dried salt crystals and they have CF symptoms, it's probably a better indicator that they will likely test positive.... I wish I had a dollar for every parent who posts to the boards about licking their kids and thinking that meant they did or did not have CF....it's kind of like the sweat test itself.... it's only good when you have a very high positive number.... but not everyone does.