IB has an annoying habit of changing the statement retrospectively. I complained about a bad CASH settlement price they used 233.45 instead of 233.86 a difference of USD200 per futures contract. Next thing I know my original statement does not have the original entries. A later statement shows some CAO transactions. This is akin to fraud. Not to mention if your leverage is high you could get margined out of a position because of a mistake they have made on a locked option position. This behavior is unacceptable. Pity because otherwise they are not a bad broker.