Hi, I still get the mess. The only thing I notice is an additional construction line on the left-most arcs union.
I went further and tried locking down both spline used for the bottom and then created two more for the sides and while they remain blue (not fully constrained) they cannot be manipulated. If the earlier two splines that are now where I want them to be are unlocked then they both blow up when I'm trying to manipulate the third that's even more remote than the first example. It's also a chore actually selecting things, often taking two or three clicks to work. The process thus far is tiresome and anything but intuitive for me.
Happy Holidays! 
http://autode.sk/2hnbr6g
http://autode.sk/2i5Gjbb