The 'magic scores' are so frustrating sometimes...you know your ds is truly gifted, but it just doesn't 'show' on a certain test...Our county has the same cut off but luckily also figures in reading level, outside work, etc. (I think this is partly because the test they administer is not quite so detailed as a WISC).
It added up to mostly looking at achievement rather than potential, which was another thing that irked me since I figured the whole point is to take a child with a lot of potential and help them achieve good or even great things.