My question involves child support in the State of: Virginia

I have physical custody of my daughter who is 6 yrs. old. Child support & visitation is court ordered.

Ex and I had a disagreement over the weekend and he threatened to petition the court for a change in physical custody of our daughter (he doesn't like the babysitter I use all of a sudden).

To date, he owes over $4,000.00 child support (from 06/2007 to 08/2008). Can he even petition the court for a custody change if he is behind on child support?

I haven't taken him back to court for failure to pay child support, because he's always made me feel bad about it, and I really don't rely on the child support.

Any advice would be appreciated. Thank you!