The pattern reads:
"...Increase round: [K1, m1, k to 1 st before end of needle, m1, k1] twice.
Divide 20 sts evenly among 4 needles (figure B). Work Increase round every other round until there are 48 sts. ..."
It should say that after you split the 20sts you should only work the increases at the beginning of needles 1 & 3 and at the end of needles 2 & 4--keeping only 4 inc per inc row, instead of the 8 that are implied.
Thought someone should put it out there for people to see.