This morning, 10-6-08, I cancelled one order in IB, then executed another. Apparently the first order did not cancel. Suddenly I noticed I was down over $400. Even though I had set a default 20-pip stop in TWS, the stop did not trigger. When I called IB -- and spoke with 4 different people, 4 different times -- they said it was a "parent-child" order, the second order being executed less than a second after the first (I don't know how that's possible, but anyway...), and that I set a buy-stop rather than a sell-stop. I've been trading on TWS for a couple of years and I have never managed to do what they say I did. I examined my trade logs, and no matter how I explained it to them, they say it's my fault, and not their problem. If I could find another broker whose datafeed works with Fibonacci Trader, I would switch brokers in a heartbeat.