My self-patterning yarn started doing weird things, but I was in denial and kept knitting:
But along came a KNOT and I knew I had to rip, find the right place in the sequence and join. So I pulled out yards and yards of yarn fom the skein until the right color came out, only to realize that the yarn had been knotted backwards. Argh! My skein was a mess, but I went back to the store and they wound it for me again, so I can keep knitting with the colors in the correct order. I'm not sure I can weave in the ends in the middle of the sock, though.