I've had AT fail or rather corrupted FMC input in the boeings causing the AT to command idle thrust in cruise, and that is something you notice cause they..err..move
Yes well thats a Boeing problem isn't it. I've been on the "Scarebus" for 3 years now, I've had one flight computer fail on me, and that was just after start up. Its a pleasure to fly, and as long as you know the systems and WATCH THE FMA, you'll always konw what its doing/trying to do.
As it is with any aircraft, if you don't like whats its doing, take the A/P out and do it yourself.