FSPassengers is messing up my aircraft

[Piedmont700]

So I took the advice of my fellow VATSIM pilots and purchased FSPassengers, and let me tell you, I love it. It's nearly perfect.

Nearly.

You see, whenever I fly with it, it seems that my aircraft handle... funny. The 727 that usually skyrockets off into the stratosphere loses
airspeed at a 500 fpm climb with throttles wide open, gear and flaps up, and a tail wind. A 737-200 that will usually stop on a dime and
turn on the same currency is found to be oafish and sluggish on the ground, often running off the runway, scaring my passengers.
Sometimes aircraft will randomly bank, without input from me, and we will crash. The first time it happened, FSPassengers told me there
was no induced failure in the a/c and faulted me for pilot error. I calibrated my joystick. It happened again, the exact thing, in a different
aircraft. I declared an emergency before I crashed. Again, FSP told me it was pilot error.

So. If FSP isn't giving me malfunctions, how the heck can I make it leave my FDEs alone so I can fly the aircraft that I've learned to fly, not
some elephant with a dwarf on it's back (to use an odd family expression)?

I've used your .ini file editor, but for one thing, I don't know what to change, and when I messed around with some settings, trying to make
it lighter, I noticed no change.

[Drew]

When you added fuel and pax, was the plane over the MTOW?

are you using a plane loader (not the fsp one? )

couple of FAQ that may help

http://fspassengers.com/?action=faq&question=66
http://fspassengers.com/?action=faq&question=64

[Ryanamur]

Maybe before the plane was empty with only fuel on board. Now that it's full, it should behave differently.

Make sure that when you load that you don't only load the fuel on one side of the aircraft.

Phil