I also experienced another DEMO error with several LIMIT ORDERS.
Although it happened shortly after the FED rate cut, the market (RTY) in this case,
went well above 2 limit orders on the DOM and then the price fell heavily but
with no fills on the limit prices. No Error, No fill and the orders still in the markets.
I guess the DEMO feeds are very different then the actual live feeds.
Thanks for any future inputs,