[ODE] zero size in dNormalize4()

[Remi Ricard]

Hi,
> What causes the ODE Message 2: vector has zero size in dNormalize4() error?
>   
I saw this error message when I played with the Hinge2.

If the error is caused by  Hinge2
When setting your axis in Hinge 2 You must make usre that your new axis 
doesn't give you a
zero length vector when multiplying your new axis with the one already 
there (the one you are not
changing).

Sometime to get what you want, you might have to make a temporary step

Remi