I've been looking at the Sep 07 / Jan 08 spread in Soybean Oil (on eCBOT) for a week or so, and have been bidding many days in a row to enter into that particular spread - using IB and a combo of these two contracts. However, today I had a very strange experience - when entering my bid I got an error message saying "Contract not supported". Now, entering single orders either way in both the Sep07 and the Jan08 worked fine. But entering orders into any calendar spread in ZL was simply not possible. I tried ZM and ZS just to test, and this worked as it should. After getting in touch with IBs customer service I was told that they didn't support this order anymore, but I think the person on the other end wasn't too certain about that. I also got told it was the exchange which didn't accept it, but since eCBOT accepts calendar spreads in ZS and ZM it would seem strange they don't accept the orders in ZL. Can anyone shed any light on a possible change of order policy between yesterday and today on the ZL contracts with eCBOT? Or has anyone experienced a similar problem with Interactive Brokers today?