Revolute Joint spring

Hi, I want to apply a spring to revolute joint. I have used next code:

NxOgre::RevoluteJointDescription rjDescriptionRightToes;
rjDescriptionRightToes.mJointFlags = NxOgre::Enums::JointFlag_CollisionEnabled;
rjDescriptionRightToes.mLocalNormal[0] = NxOgre::Vec3(1, 0, 0);
rjDescriptionRightToes.mLocalNormal[1] = NxOgre::Vec3(1, 0, 0);

rjDescriptionRightToes.mRevoluteJointFlags = NxOgre::Enums::RevoluteJointFlags_SpringEnabled;
rjDescriptionRightToes.mSpringType = NxOgre::Enums::JointSpringType_Acceleration;
rjDescriptionRightToes.mSpring.mSpring = 50000;
rjDescriptionRightToes.mSpring.mDamper = 50;
rjDescriptionRightToes.mSpring.mTargetValue = 0.5 * Ogre::Math::PI;

//crear revolute joint
rjRightToes = mScene->createRevoluteJoint(NxBones[1], NxBones[4], rjDescriptionRightToes);

RevoluteJoint is created correctly, but the created spring doesn't works. It seems like it haven't been created...

Any idea to create correctly a spring?? Thanks