Rich,
I had a similiar situation happen to me about 12 years ago. I was delivering pizzas the summer after I graduated high school was driving a beat up chevy monte carlo I got bagged with an expired inspection sticker got gigged the 35.00 bucks I sent the check in within the 21 days. about 45 days letter I get a letter from the RMV stating my license is about to be suspended for non payment. I went into the local RMV office is Roslindale and was told by the old bat that I must have never paid it, and the suspension was gonna happen. I called the bank and what do you know the check cleared. I got the cancelled check and went back to the registry. the old bat proceeded to tell me that is my fault because I wrote my license number on the check instead of the ticket number, and thats why they didnt credit me with paying the citation. Lesson of the story is follow up follow up. The trooper in this case did the right thing by you. He could have slapped the cuffs on you and hauled you in.