I don't know. The problem may come from the Stop Loss, or the Take Profit: remember that it can't be too close to the price. Check with MarketInfo() that 15 pips is far away enough. Check all the variables' types (including what is returned by the functions) and make sure the takeprofit is normalized (right number of digits). Slippage issues interfering with SL/TP are not documented but might happen?

A remark: a takeprofit of 15 pips with a stop loss of 153 pips is very strange...(unless it is an emergency stop loss for ~9/11 events and you normally close the trade well before that).