what kind of wire did you use for each part? I was trying to figure out how you got the twisted part to stay.
for the center made with smaller beads, i just used soft flex wire. (this is what it looks like: http://www.michaels.com/art/online/displayProductPage?productNum=bd0001&channelid=
for the big beads that twist around, i used 24 gauge beading wire. (this is what it looks like: http://www.michaels.com/art/online/displayProductPage?productNum=bd0137&channelid=
it basically stays in that shape without much help. when i twisted the wire and beads around the skewer, i twisted so that the rotations were side by side, as close as can be. after i twisted the entire length of beads around the skewer, i slid them off and gently and evenly made the distance between the rotations longer. i then shimmed the center wire through the spiraled beads. to make the spiraled wire stay in place, i just took the end of the wire and wrapped it several times around a piece of scrap wire, slid the bundle off of the scrap wire, and then slipped the soft flex through the hole in the bundle of wrapped wire. it's a pretty rough way of finishing it off, but i'd never done it before and didn't have any materials on hand that could make it smoother, but i'm sure there are tons of other ways to do it.
but no, you shouldn't have a problem with the spiraled wire untwisting. as long as you use wire with a heavy gauge, you shouldn't experience any untwisting.
also, i saw a sweet one of these at our bead store that keeps the "sprialage" as close as can be together for the entire lenghth of the necklace. that one used the solid wire for both spiral wrapping and for the center wire. it looked way cool too!
hope that helps!