My inexpert advice on this, from a year spent dealing with a special education teacher who simply refused to follow an IEP, is that you need to immediately start documenting when her accomdations are not being followed. Keep a journal and note what she or the teacher tells you. Make a polite suggestion to the teacher that you are avaiable to meet with to start coordinating accomodations. Make another polite, but firmer suggestion if it still does not happen. Then write a letter, suggesting that parts a, b, and c, from the 504 be followed, and give a copy to the principal and whoever else may need to know. Etc.
Of course, it could just be back to school craziness, but a little documentation and polite suggestion never hurt.
