Why wouldn't a kid become lazy if they get 100s on all their work with Zero effort? Or some concieve that all kids are born 'lazy' but through repeated experience with challenging learning in school, learn to harness their anti-Lazy power.
How to cure? Look into the literature on 'reversing underachievement' - sounds like you should consider this a DIY project for afterschool and not expect anything more from the school than babysitting at this stage. Perhaps after you've gotten work out of him that you can show the school they will be more useful, but for now you need to stop waiting for the school to help and 'buck stop' for a while.
Helpful books include:
http://books.google.com/books/about/The_Myth_of_Laziness.html?id=0-Vt1CtJ0tUChttp://books.google.com/books?id=GH...sylvia%20rimm%20smart%20kids&f=falseNot fair but since when is life fair?
Grinity
