It sounds like either they passed these new regulations specifically to get the money from your group or prevent a type of fundraiser you might be doing, or someone is misinterpreting the new regulations.
My school district just put similar rules into place, and while some people were up in arms, after looking into them some more, we realized that they were designed to stop schools from participating in a particular kind of fundraiser that was taking time away from class instructional time. If you are doing a fundraiser in the name of your organization (not the school), and you're just passing out information through the school, I think the school is hard pressed to keep the money you raise from it. If you're doing a fund raiser during school time and on school property, that might be different. Hard to tell without reading the regulations and knowing what kind of a fundraiser you are talking about.
We are a small school and have one fundraiser a year and it's held at the school. The money raised is used for the students and teachers. The school board just past new polices and boosters and parent organizations. If we have a fundraiser on school property then we have to turn over any monies raised above our costs to the principal to be put in the school activity fund and used as she shes fit. We have had fundraisers outside of school and wasnt successful can they required us to hand over the monies raised.