Mark thanks a lot for your help, I tried all you suggest me without any success.

But maybe a find something interesting. i think problem reside not in 757 installation, the problem is the way VC is loaded. Infact if I choose fly now my 757 is loaded in VC directly amd nothing works as said, ok?

If I switch to 2d view and then back to VC now all knobs, button and levers works perfectly. So, what can be? It's a very strange problem.

Do you have any suggestion? Some tip I can apply to solve this annoing problem? Thanks in advance.