Shari - I was going to say the same thing. When DD now 8 was in kinder/1st grade the same thing happened to her too. Her reading level had been determined by AR testing and STAR reading tests and the books she selected for those tests were not at her reading level, but rather at her interest level. (Her interest in the illustrations in the books at the time. wink ) For her if the book's pictures were well done it was a much better book and much more worth her while than a book more at her reading level, but with lower quality pictures. Her ability and interest in art and illustrations is now stronger than ever, so I think she was too busy investigating her new found artistic ability than in improving an already amazing reading level.
Her level has increased quite a bit since then (to the point that her teacher had to call the test makers to get help understanding her comprehension results on a recent test because they were so high she was sure there was a problem with them. blush ).