I can so relate - I have no magic answer - will be interested to see what others write. I thought that if I sat and had a real heart to heat with the teacher and guidance team explaining my concerns and worries that it would help - it didn't help anything other than with getting the same answer over and over - we don't differentiate, we don't accelerate, we don't pre-test....we are already crunched for money and time and you can't expect us to make exceptions for one student in class - even though he has an IEP!!!
When we tried public school for First Grade DS was doing math/reading several grade levels ahead but the teacher was dead set determined to make him do repetitive worksheets like all the other kids in the class of color the animal that starts with the letter D, circle in the correct number of balls that shows the answer to 4+2. He was bored out of his mind and he is a very head strong kid so he began to refuse to do his work. The teacher then pulled the card that she can't move him onto harder work if he is refusing to do the easy work. I tried to ask for her to do a pre-test but she said it was too much work and not fair to the other students (HUH???) and that they don't do that in their school. So my son was miserable - when he would refuse to do his work, she would send him out of the room (again - huh?) and then one day she decided she would "show him" by sending him out of the classroom with 2 sets of sheets front and back with 50 math problems on each side - so a total of 200 math problems. He completed all of them and got every single one correct and sat bored out of his mind in an empty room for 2 hours. We left to homeschool after pounding our head on the wall a few times :-)