Oh I so get you - My older DS did this just last week - 0 for not turning in 2 homework assignments in a row and 100 and 98 on the 2 tests that week. Lo behold his grade has slipped to a B and he is all upset. I told him to go talk to his teacher if he wants to get it fixed. I suspect he must have been dreaming in class when the teacher asked them to turn in their homework.
I hope your DS and mine learn to organize their work better and realize how important it is to not just do the work but turn it in on time.
