Hi Barry
So sorry for the trouble.
Yes. It must be an old modification that I did on "BoundingBox-infos" node and forgot to register.
This is the fixed .nod file. Check if this one works.

Hi Peer
Yes, Michael's solution should be easier and faster. :)

I'm not sure if I understood the accuracy problem.
I think those "very close" points you mentioned are in a same height.
Curve below has 4 intersection points on highest location. all with the same "z" value. (values from nodeeditors's info panel)



Another test with moi's dimension tool:
I've made the blue line like this:
curve >> project >> use CPlane as target >> create a straight line on projected line
red line : nodeeditor

Hi MO,

Your results are pretty darn accurate. I'll give that approach another try.

- Peer

Thanks Mo,
working fine now.
Cheers
Barry