The summer squash pattern had a mistake (it can happen to the best of us right?).
The pattern should read;
Rows 30, 32, 34-39, 41: sl 1, k1, sl 1, then knit all sts to end of row
Rows 31, 33, 40, 42: k1, sl 1, then knit all sts to end of row
I hope this clears things up!