Thanks for the information. I know what you mean about things not always running smoothly in MT4 contests!
Ray is an EA, but despite that he's now trading happily in this particular contest. However the first time I turned him on I got a different sort of error to the ones mentioned above. It seems that despite hailing from Australia, Vantage's contest server is running in 'US FIFO' mode, and won't accept market orders with built in stops and/or targets.
Any chance that is the cause of your own EA's difficulties?
Reality is merely an illusion, albeit a very persistent one - Albert Einstein