A reader wrote in today,

Your blog is wonderful, thank you! I have been noticing that ISEE scores for the lower level exam have been coming back very low as well. Is there any reason for this, or information on this phenomenon on the Internet?

Possible reasons I have been able to track down so far from my tutor sources: some overly difficult material not suitable for 5th graders, the insertion of beta questions throughout the test that may have thrown some test takers off, and possible misscoring in some cases.