It's probably some really small technicality that no one would normally care about. My advice is to have your mentor try to set up your team as a completely separate entity from the school, and instead have the school as one of your sponsors. That way, your team is entirely responsible for their own funding. However, you need to have an adult mentor who really knows the laws about this sort of stuff, otherwise you're liable to get in even more trouble. But, in my opinion, it's much better for the team.
Of course, if you can get your team set up as a 501c3 organization that's completely separate from the school, that's the best situation. All donations are tax-deductible, your team controls it, and you don't have the politics of the school board to go through. If you have a student whose parent/relative is an accountant, or if you can convince a nearby accountant to donate their time to your team, this would be the best course to follow.
In the short-term, if you need to talk to your school board, I'd advise that you contact each member of the board individually. Have a student (or two, or three...) talk to each board member about what FIRST is and why it's so great for the school. Maybe even have your mentor discuss potential legal issues with a few of them. After you've won a few over, bring up the issue at a board meeting. Our school district usually holds a public-accessible board meeting every month. Have your team wear their shirts and attend the meetings. Get a bunch of family members and friends to wear team shirts and go as well. Politicking is all about showing that you have strong support behind your goal, and that's most visible when a large group of people at the board meeting is wearing a shirt advertising your team.
Good luck!! Hope it turns out for the best for your team.
