If as settlement was made in the past, does an insurance company have the right to sue you?

GOt in an at-fault accident in 2004...at the time I had no insurance. This claim was settled out of court years ago, but now, the opposing party's insurance company is claiming I owe them $40,000 for bodily injury done to their client. I guess the opposing party sued their insurance company and now the insurance company is trying to get compensation from me. Do I have to pay for it even if the claim was previously settled in court?