If it is a math error, I hope IB fixes it quickly--since it would be easy for them to fix in their 1009's and ScheduleD-1 generators' algorithms. It is a shame that the same company adds up the same sales numbers differently and create one more form of discrepancies in its 1009 and ScheduleD-1 worksheet's sales proceeds. Most other brokers at least have the math portion straightened out. It is still a good sign that IB now has less errors than the last year in your case.