Optimization question - Optimizing vs Backtesting?

Hi
I know successful optimisation is no indicator of future profits however I have a problem. On optimising my program for the last 6 months I make a substantial profit, however when I take that optimised data and run it as a backtest over the same period I only break even. Surely these results should be the same?

Thanks

Max

Yes, if all the conditions, variables, spread, data, date range are the same then yes the runs will be the same. What was the spread during the optimization ? what was the Spread during the single run ?

thanks for the reply. I assumed the spread would be the same. Maybe I need to check with alpari?
ta