I am having the same issue on the same model. I ruin about 1 cutout of every 5 with this issue.
Are you using mach3?
If so what version. I think 3.041 may have had a bug that relates to this, But I havent upgraded beyond that yet.
Bug is supposed to be that the arc good pause was left out.
But if you are not running mach3 and find out why it is doing that, post your results.