poissons ratio effect on Stress intensity factor

Hi :

I am obtainning the Stress Intensity factors along the front of cracks in a 3D FE models (ANSYS). The loading mode is mixed and Ki, Kii and Kii should be estimated. I have noticed that the SIF  strongly depends on the poisson's ratio but i understand Ki does not depends on the elastic properties of material. I know ANSYS calculates the SIF from the displacements at the crack tip using E and mu, but i did not expect so huge differences in SIF values, In fact all analytical predictions for SIF does not depends on poisson's ratio....

could anybody help me to understand where the problem is?

Thank you in advance.