Addendum: After finding an egregious and unfixable error, I carefully tinked back on the colorwork sock, to the point before starting the colorwork. At that point, I should have had 36 stitches on each needle (I knit socks on 2 circs). In fact, I had 39 on one needle, and 42 on the other. I tinked back one more row, on the purl side so I could see dropped stitches and inadvertent yarn-overs. That gave me 36 on each needle, so I proceeded with the colorwork as previously planned. Since, to get the width I need, I had to increase the stitch count from 64 to 72, it will take me longer. On the other hand, I seem to have hit on a way of holding the yarn that doesn't cramp my hand, so I can work for longer periods of time than I had previously.

After getting a good start on the sock, I went back to the sweater. Sleeve #1 is almost done. I could be wrong, but it looks like it's going to fit on the first attempt. I hope.