In my FSX I noticed two new things with SP1. First is that I can cruse with the LearJet on throttles on idle (air speed ~210). LearJet is NOT that good of a glider.
The second problem (only sometimes) is when I put my throttle on idle and then I change to external view, the sound of the engines is like I have a full throttle. Sometimes it helps if I cycle the views.
This problems came with SP1 (for me). The only thing I did before SP1 install is that I removed fsx.conf file and rerun FSX to build a new one.
Have a nice flight.
BTW, Sorry for my english.
EDIT: and yes, I recalibrated the joystich - throttle is idle when it should be.