Sorry if I misunderstood what you said when you said If this happen to experts like you Markoz,  think about the struggle a newbie like me has to undergo. It was just how it came across to me. :-[

I was also saying that I had only been using complex airliners (aircraft that use an FMC) for a short time, (only about 3 months) when Captain Sim released the 767-300 Base Pack v1.0. So I was still learning the complexities of these types of aircraft at that time, yet I never had it do what yours is doing to you.

Unfortunately, I have no idea of how long you have been using aircraft that use an FMC, since you've never really said, so I'm guessing it is more than 3 months. :-/

One more question.
What Navigation Database are you using? The one thtat comes with the 767 v1.5? Or do you update them monthly with NavDataPro or Navigraph subscription(s). I'm only asking because I will base my tutorial on whichever version you are using (I have all of them from 1002 to 1307 (Navigraph)). I have a 13 cycle subscription with NavDataPro, but I don't like the way it works so it is out of date (I haven't updated it for a few months now). Besides all that, I found both to be very similar anyway, especially with the changes that Navigraph made since their renewed AIRAC cycle 1301.