You should refile your tax return by mail with proof that you can claim your children.
Sent with your tax return copy of school records and insurance card of your dependend.
The IRS will request the person who claim your children to also show proof that they
can claim the children on their tax return. The IRS will not tell the person who first
claim the children who initiated the audit.
If he live with you for over 6 months in 2007 the IRS will give the person who made the most money the right to claim the children.