TOS typically used to route my non-marketable limit orders to ISE and my marketable orders to PHLX. Cool, no problem. In the last few weeks, it seems that my non-marketable orders are being routed to CBOE where they tend to sit. I did a little test this week. I had a limit order working at CBOE and I was the nbbo for over 15 minutes. I routed an identical order to ISE and was filled within seconds. I then had plenty of time to cancel the order rotting at CBOE. Has anyone else observed this scenario????