I just purchased this software and this has been frustrating to me. I'm not sure if it's a PDMG problem or FS2Crew, but with five tutorial flight attempts from SFO-LAX, and the FMC completely programmed, I lose the ability to "lock-in" the autothrottle. I did read about waiting a few minutes before take-off to arm it, but it just won't stick, even then. Any ideas would be appreciated. Thanks