I don't think that means there is a learning disability. You may have found that, for example, your school is not as good as you thought it was. If someone is an A student at a mediocre school versus a B student at an excellent school, which child will score higher on an Achievement Test? Perhaps the B student.
My hearign-impaired son scored in kindergarten on every part of the WISC at 98-99% (percentile) and 40% (percentile) on PRI, the processing speed. At the time, we didn't know he was hearing impaired since he had passed all of his hearing screens. An over 50% spread like that does indicate a learning disability.
You may be seeing that your child has raw intelligence that is not being channeled the way you feel it could be.
