Generally, probation for a DUI has a condition that you not operate a motor vehicle unless you have insurance. If the probation department pulled your traffic record, they would have seen the ticket. If you had insurance and took care of the ticket, be sure to take that to court with you.
Yes, it can come up later like this. There are potentially serious penalties for this probation violation with many courts imposing what they believe is a mandatory 30 day jail revocation. With such serious penalties on the line, you need to contact the attorney you had on your case or hire one. If you can't do that, contact the court and ask them why they set the review hearing. It sounds like you may have mitigated the insurance ticket by showing them you had proof either at the time or shortly thereafter. Even if you have insurance now, if you were convicted of the insurance ticket there could be potential problems. It's best to hire an attorney and bring your proof of insurance with you to the court date. Make sure you don't admit to any violations of probation without an attorney present on your behalf.
It's hard to say what, if anything, they are going to do to you about this. If you had insurance and can demonstrate that to the judge you did at the time then you really shouldn't be in too much trouble. A lot of time with probation there is something in the fine print that says you must report all law enforcement contacts to probation. If you got pulled over and ticketed and didn't immediately call probation and tell them about it then they can violate you for this. A lot of times your probation officer will tell you what they are looking at doing in court if you give him or her a call and talk about it.
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