Ex wife lied on childsupport gross income?

My ex wife lied on the original childsupport gross income. She omitted the rent for a home she rents out. She has recieved around a thousand a month for three years for the rental. Now after I lost my job and couldnt find one for a while, she is taking me to court for arrearments. The amount of money I have paid her because of her omission of income, equals my arrearment. She commited perjury, I paid unwittingly the amount set by the court thinking that it was under oath a correct figure, as was mine. WRONG...... now back to court. Will the judge see her perjury, throw out the original calculation and grant me credit for the amount I was swindled out of. It is almost exactly what I owe her in her claim of arrearage. Actually she'll owe me 8.00. She tried to screw me to the wall with this omission. It was intentional and she has text messaged me admitting the money was not claimed as such.