Many thanks, Dan. I think it is shere psychology - one prints something into a box and one expects that the printed content pops up in the box immediately. If not - one gets exited and reloads the model. It is just what happened to me. And this has led me to the second blunder, which I afore described. I put it in other words now. If we have a number of variables but by some mistake excluded one of the variables. For example we had a variable 470 pF as =A Then we have gone to the list of loads and replaced 470 by 400. It means that the variable is no longer active isn't it. Of course it was a mistake - you should change it in the list of variables, not loads. But you did not noticed it. Then you returned to optimization and started it having all the variables ON. And the variable =A (that stand for the cap 470pF) will look as if it takes active part in tuning, it changes somehow in the table of active variables. In my case it changed down to 150 pF, whereas it really remained 400 pF in the model. I was unaware that it does not change and it is strange that the program does not give any warning in such a case, isn't it?