CoolP

I tested with FsBuild and FSX flight plan. Boths works perfect.

I suggest the following for your test flight:
1- Open FSX
2- Select 707
3- Open Flight Plan and create one
4-Save fight plan
5- Click Fly
6- 707 ready
7- Receive you ATC and Taxi clearance
8- Takeoff
9-Transition to first way point
10=turn A/P mode to NAV
11=Here yo go..., Fly with most sophisticated 707 navigation system   :D