I'm not personally familiar with the K-Bit, but there's an article on Hoagies that talks about it vs other standard intelligence tests that you might find useful, here: http://www.hoagiesgifted.org/iq_varies.htm

In brief, it sounds like this is a very brief test and covers only some subtest areas, and if not testing all the child's areas of strength, they could definitely score lower vs. using a full-length test.