Here is the english version:

If you want to understand logic, you have to know Horner's scheme:

It is pretty simple but effective algorithm for evaluation of polynomials.

Note: There are some more functions in code, than it's really needed. I have added those in process of debugging to check out certain segments of code.

Can you please send me exe file of my code? I want to check out that.
I suspect now the source of the problem is maybe 32-bit compiler on 64-bit machine.