What's broken?!?!

Hi All,

I'm using a simple trailing stop to close each trade taken, here's the code:

  // Trailing stop, first search for positions using this symbol and this robot (label)
            var symbolSearch = Positions.FindAll(label, Symbol);

            foreach (Position position in symbolSearch)
            {
                //Define position direction
                if (position.TradeType == TradeType.Sell)
                {
                    // Calculate distance position has traveled
                    double distance = position.EntryPrice - Symbol.Ask;
                    // Check if distance is greater than trigger to start trailing
                    if (distance >= TrailingTrigger * Symbol.PipSize)
                    {
                        // Calculate new stop loss level
                        double newStopLossPrice = Symbol.Ask + TrailingStopLossDistance * Symbol.PipSize;
                        // Check if new SL level is better than current level
                        if (newStopLossPrice < position.StopLoss)
                        {
                            // Modify SL level and set take profit to null, we only exit when the trailing SL is hit
                            ModifyPosition(position, newStopLossPrice, null);
                            Print("Short Position ID = " + position.Id + " new stop loss = " + newStopLossPrice);

                        }
                    }
                }
                //opposing code for TradeType.Buy
                else
                {

                    double distance = Symbol.Bid - position.EntryPrice;

                    if (distance >= TrailingTrigger * Symbol.PipSize)
                    {

                        double newStopLossPrice = Symbol.Bid - TrailingStopLossDistance * Symbol.PipSize;

                        if (newStopLossPrice > position.StopLoss)
                        {

                            ModifyPosition(position, newStopLossPrice, null);
                            Print("Long Position ID = " + position.Id + " new stop loss = " + newStopLossPrice);
                        }
                    }
                }
            }
        }
    }
}

I'm back testing using Tick data and the result can be seen in the image below... The trade should have locked in a profit of over £50 but instead realized a loss of over £7... 

How can this happen?!?!

Thank you in advance...