Excellent I tried to replicate what you were seeing and the only way I could get it close was with the gust lock engaged so I'm pleased that was the problem ;-) It affected all engines on my system but I've found that the Vanguard runs slightly different from pc to pc (don't ask me why cause I have absolutely no idea) :roll:
The important thing is that you're up and running in good order with the right kit so job done ;-)