Hatred of Knots

We had a good friend as a house guest for the past week, so I have had no time with my loom. But Gus got a job (woo hoo! we plan to party tonight!) and now I have the house to myself, so I decided to spend a relaxing day putting last week's warp onto the loom!

I designed my own version of a "crammed and spaced" scarf for this warp. It involved a lot of math and a ton of graph paper because I wanted to make the most of my limited tencel. I ran out of green tencel as I was measuring the warp, so I decided to add a taupe border. This meant measuring one of the border edges separately as a second warp chain. Here are the two warp chains hanging out on the floor in front of my loom:
Now, I've made several warp chains in my time. And I never worry about knots, because they have never been a problem. I got the warp all sleyed and threaded and then started to comb it out and wind it on. It did not take long to realize that something had gone terribly wrong with that second warp chain. After winding about half the warp it was in such a knot that I couldn't continue. This has never happened to me before! No matter how badly it tangles, it always combs out without too much fuss. But I can't get this straightened out, and I pride myself on being able to undo almost any knot. What could I possibly have done this wrong?
I'm attempting not to get frustrated, but I did spend a lot of time planning this project and I don't think I have enough yarn to redo this border. It's time to walk away.