Fixed joints work ok, so it must be 'you bugged' :D
Take a look at the 'CarDemo-SphereWrapCylinder.bb' demo, it contains use of the fixed joint. It boils down to...
Joint=dJointCreateFixed(World,0)
dJointAttach(Joint,Body1,Body2)
dJointSetFixed(Joint)
I'd guess you've forgotten to remove some (or all) of the now redundant hinge functions... dJointSetHingeAnchor() / dJointSetHingeParam() etc.
If you're still getting errors, post some code and I'll try to help ;)
Take a look at the 'CarDemo-SphereWrapCylinder.bb' demo, it contains use of the fixed joint. It boils down to...
Joint=dJointCreateFixed(World,0)
dJointAttach(Joint,Body1,Body2)
dJointSetFixed(Joint)
I'd guess you've forgotten to remove some (or all) of the now redundant hinge functions... dJointSetHingeAnchor() / dJointSetHingeParam() etc.
If you're still getting errors, post some code and I'll try to help ;)