“ My tax person stated that this is not true and that I did not violate anything. My custody paper work does not identify who claims who, just who has custody. Did I do something wrong and is my tax person wrong?”--> It depends o the situation; the custodial parent is the parent with whom the child lived for the greater number of nights during the year, NOT FOR MORE THAN ½ OF THE YEAR. The other parent is the noncustodial parent.If the parents divorced or separated during the year and the child lived with both parents before the separation, the custodial parent is the one with whom the child lived for the greater number of nights during the rest of the year. In most cases you, as the custodial parent, receive the exemption, but typically, if the non-custodial parent is paying significant support to the custodial parent and/or exercising more than usual visitation (but not more than the 50% of the time which would trigger the IRS rules to allow claiming the child as a dependent), the non-custodial parent has a valid claim to the tax benefit of claiming the child.in other words, if the non-custodial parent wishes, he can file it if the "special rule for children" applies. This rule applies if the child received over half of his support from the non-custodial parent throughout the year or spent time in his custody. It also applies if you, as the custodial parent, agree not to claim the child and give the Form 8332 to him.
“Should I ammend my tax claim for 2010 and allow my X to claim the son?”--> It depends as said above.