Who knows what causes a difficult warp to behave. Whether the weaver comes to grip with the combination of tension and beating a warp requires, or whether eventually they get tired of proken threads and swap them out, sometimes persistance pays off.
This warp is the one of random ends of old 60/2 silk that I've been working on for a while. It's given me a lot of trouble with broken warp threads, and also with twists in sets of warp threads from the way I beamed the warp (the idea of winding sets of six threads on a cone and treating them as a single thread for sectional warping clearly needs refining). The fist scarf I wove on this warp had a lot of broken threads which will require mending when I finish it. Even the start of this scarf gave me a lot of trouble with broken warp threads in the first couple of inches - until I realised that all of the breakages were happening in my new substitute ends. I was replacing good silk thread with weak!
I'd really begun wondering whether persisting with this warp was worth it, or whether I should just bite the bullet and cut it off - but the realisation that it was the substitute ends causing the problem now and replacing them all fixed the problem (that was not the case with the first scarf, as it was the weaker beamed ends that were breaking). It's been a long, slow process, done in between work, a couple of very social weekends and yet another cold. Having swapped out all the weak ends, I've now woven several feet of this scarf without any problems. The design is a treadle-controlled undulating twill of my own design, woven on a straight threading.
I had, once I'd finished this warp, planned to tie on another 60/2 silk warp to it to do another series, this time in blues and greens. But there are so many substitute threads hanging from the back of the loom now, that trying to replace those on the beam would be more of a headache than it's worth. So now it's off to the drawing board to see which of many incipient projects I'm going to do next instead - I suspect it's going to be playing with more handspun.