Well, anyone who has used IB for a while will know that customer service can be a bit hit-and-miss sometimes, and I know some IB reps (who seem to be able to get things done) frequent these boards so I'm going to post here as I need clarification on an issue which may also be of concern to other traders of US equities. I have an outstanding trouble ticket (ref T954290) in which I gave details of a stop order which failed to execute on 27th June. To answer the obvious questions : Yes, this was during RTH, and yes, I am talking about STP orders and not STP LMT. The initial response I received was : "The issue preventing the order from executing does not appear to be related to how the order is submitted. I am currently seeking additional detail regarding why the order did not execute. It appears that the order was triggered and was attempted to be routed for execution, however, no trade occurred." Followed shortly afterwards by : "It appears that our system was attempting to route the order to NITE during a time when they were having technical problems and did not accept the order. The issues appear to have been resolved by 11:13 est. There do not appear to be any errors with how the order was submitted." (11:13 est would be about 1h15 after the order should have executed). What this seems to be telling me is that this IB/TWS has no way of recognising if a stop order is not "accepted" at the location to which it has been routed and therefore no procedure for re-routing in such a case. In other words - any of my stops could fail to be executed at any time without warning or subsequent notification. This I find somewhat scary. Can an IB rep confirm I have understood correctly? I have asked for clarification on the trouble ticket itself but have had no update for 48 hours.