This sounds exactly like when my brother now 17 was in junior school at a similar age, his behaviour changed and he was always feeling sick and having the day off, then one time there was a school trip which he paid for and the BAD teacher said it had gone missing and he couldnt go on the trip, he was so upset and swore the teacher took the money (we were convinced she pocketed it) she was young and vindictive the sort of teacher who always picks on one child and makes their lives a misery, seems often to be boys or the poorer kids, think it makes them feel powerful! anyway as noxumolus said, he was taken out of school and taught at home, which saw a vast improvement to his behaviour and he joined high school in the first year, then came the teenage years...........!!!