Once again, I've never been able to solve this issue.

Once I'm ready for departure I hit the EPR and then once airborne I hit LNAV/VNAV and then AP Engage (L)...as it climbs and usually after FL200 or so the throttle starts to go down and then I have to hit the TO/GA or CON then it will throttle up and after a bit it goes back to idle and back up. I tried messing around with the THRUST REF SET, it will hold the throttle up at least trying to get to the assigned speed for a bit then its back down. A unistall-reinstall never fixes that for me.

I have a video being uploaded right now that shows what's going on and will post the link once its done (for some reason its 1.32GB and its a fairly short video)

Thanks,
Nick