My ex has always avoided paying CSA whenever possible, to the extent of leaving jobs when it gets to the deduction of earnings stage. He owes around £4000 in back pay at the last calulation, about a year and a half ago. About this time, he started a new job, and was in an accident at work, which damaged his arm. He was signed onto jobseekers (as far as I know, definitely benefits, and CSA said jobseekers at one point), and was having physio, etc. While he was recieveing jobseekers, £5 a week was being deducted CSA for our DD.
About 6 weeks ago, the £5 stopped. I rang up CSA, they said the jobseekers looked like it had dropped off the system, and they would have to reapply for it. Bumped into a member of his family today, apparently he has recieved compensation for his accident, to the tune of a couple of hundred thousand!
This would obviously explain the lack of jobseekers.
I haven't been able to ring CSA yet, due to working til after 6. Has anyone any idea what could happen here? Will he have to pay back what he owes, will he still have to pay us anything weekly, given that he has no actual income, but is living off this? I'm bloody annoyed at what a wanker he is, he didn't even send DD a birthday card or present last month, and when I got in touch to say she wanted to see him he replied he was in Mexico, didn't even mention he was going away, never mind make arrangeents to see her 
Posted this in chat too, hopefully someone will be in the know.