Join curves

Hey Guys,

I am having some problems joining some arcs into one curve to divide, connect with an other set of points and create a loft. I started with 5 arcs and the middle 3 joined perfectly, but the one at the start and end will not join and I don't know why. Could it be because every arc is create with 3 vector point (construct point function) and the other 2 are create with an end-function?

If you look at the images I attached, you can see that first one does  not join. When I simplify the point by turning the x-y-z-value into full numbers (without decimals) it still does not join. But when I use a note panel and fill in the exact same x-y-z-values as the simplified ones, it does join. But I need those values to be variable, so this is not an option.

Does some one know why this happen or what I can do to get what I want? I can also work with N(0) and N(2), but I don't know how to turn that into one tree. I hope some one can explain me how to solve this problem.

I thank you in advance