child support

I remarried in March 99 and obtained permission from my ex to move out of state to Kentucky. He agreed for me to move with our two minor children. We also agreed that he would have them every x-mas for two weeks, spring break, and there entire summer vacation. We also agreed to split the cost of transportation back and forth. He would not agree to legally change it in our divorce decree, and said his word was good enough. So I took him on his work and moved. We moved in April 99 and have been here since and the verbal agreement for visitation has been mantained. From the time we moved until October my husband and myself finacially supported my children. Finally, the burden was to much for he has two children from a previous relationship that he supports, and I had to ask my ex for some support money. He agreed to send me 300.00 a month. Which to me for two children was not much but it was better than nothing. He makes 38000.00 a year. Anyway this August I asked him if he would give me 400 a month and he said "NO" he couldn't afford to but would send me 350.
I am now in the process of filing with the courts for support, but will he have to pay back support from the time we moved here until the present? In the divorve decree it did state that if he didn't see the children as much as he was saying he was to pay support in the amount of 125 a week. With the little bit of money it is hard for me to pay half the transportation for the children.
Should he have to pay more for the transportation? Or is it up to me because I moved?

Since you were the one that moved, it should be your responsibility to pay for the extra costs that he incurs as a result of your move. You were lucky he agreed to pay half.

You knew all this before you moved so you should have gotten it sorted before. As regards to back CS, it depends if he was legally ordered to pay previously. If not then no.. if there was an actual court order then yes..