It's impossible for me to do a Vnav descend without exceeding the target speed, specially beyond 20.000 feets. I need to deploy spoilers and still exceed the speed. I noticied that in idle position the engines are running at 40%N1, 40%??? that's normal? Anybody have the same problem?

Please go ahead and do a forum search. There has been an extensive discussion in last days of this phenomenon.

I also had this problem. It was caused by a programmed button with "Gear Up" used with the CH Joke and FSUIPChttp://forum.avsim.net/topic/353764-the-ch-fsuipc-sp1-idle-bug/page__p__2176958#entry2176958

Yeah, I just find the topic, thanks and sorry for double the topic