I've never had a broker call and ask me to "bust" a trade, I've always had to call them. But IB used a live person to call me and ask if I wanted to bust a trade at Island for 200 shares! I shorted 600 shares and was filled on 2 exchanges at 16.50 and on Island at 16.00. Is this normal for IB with their bare bones system to care about my fills? I decided not to pursue busting the trade, but was impressed at the customer service.