Metatrader Tester

[onur]

hi

I use optimization option in strategy tester to test my stochastic expert advisor.
I choose 1(start) to 200(stop) and 1(step)to all K period, D period and slowing values and i test it.
then choose 1(start) to 10(stop) and 1(step) to all K period, D period and slowing values.
for example 5 K Period 5 D Period and 5 slowing parametres i have a different results between the wide range(1-200) and narrow range(1-10).
(i test same time frame)
tester has a bug or i didn't gave a meaning these different results.