Oh deary me! It was all going so well, too well in fact. I finished the second sleeve of Autumn Rose and had joined the sleeves to the body and worked several rounds. Then I noticed I'd made a mistake in the pattern on one of the sleeves on the 3rd row - I was on row 7. I tried to ignore it but I knew what I had to do as it would bug me too much if I didn't. So I ripped back 4 rows of squillions of stitches and I'm about to go back and do them all again.
That'll teach me not to do complex patterning whilst watching a film!