I'm having a problem with losing execution priority on orders directed to Island. I use Interactive Brokers standalone TWS and Island directed orders (not SMART routed). I have both buy and sell orders for the same stock simultaneously. When I get a partial or full execution on one side, the order on the other side gets thrown to the back of the line in priority at my price level. I suspect that my order is being removed and resubmitted. The interesting thing is that in the event of a partial execution, the order which is partially executed gets reduced in size, but maintains its priority at my price level while the order on the other side loses execution priority. Also, I can manually change the order on one side without affecting my execution priority on the other side. I spoke with IB technical support. He suggested that I was probably using an outdated or incompatible version of java. I used the link on the IB website to java.com and verified that I was running the latest version of java. Has anyone else experienced this problem? Any explanation, fix, or workaround? I hope that the answer isn't that I have to avoid routing orders to both buy and sell sides on Island simultaneously or take my flogging.