btRaycastVehicle: jittering when braking while vehicle is at a standstill

What steps will reproduce the problem?
1. modify vehicle demo, apply brake on 4 wheels instead of 2 (and increase 
braking force to make the issue more visible)
2. run the demo, accelerate the vehicle during a couple of seconds, then brake 
until the vehicle comes to a standstill, then keep brake key pressed
3. vehicle jitters/vibrates significantly while brake key remains pressed, 
while it should remain still

What is the expected output? What do you see instead?
vehicle should stay still, but is jittering

What version of the product are you using? On what operating system?
latest trunk

Please provide any additional information below.
more details in this post:
http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=9&t=8473

thanks :)

Original issue reported on code.google.com by easyrid...@gmail.com on 2 Oct 2012 at 6:56

Attachments:

VehicleDemo.cpp

Chinamming / bullet

btRaycastVehicle: jittering when braking while vehicle is at a standstill #654