Hi PaQ - there is a bug currently in curve-to-curve flow when some tangent directions inside the curves are pointing upwards towards the world z axis.

So for the moment until this is fixed you've got to place the base curve and the target curve to be both in the world x/y plane. You can have the objects that are being modified in any direction, just the base and target curves need to be in that x/y plane. I should be able to fix that up for the next release, I've got an idea what is going wrong.

See the attached example for how it can work in the current beta though.

- Michael