Thanks for posting the pattern link salmonmac. It helps a lot when we can look at the actual pattern..
Helre's the st pattern:
Linen Ridge Stitch (in the round)
Row 1: purl
Row 2: *(wyib sl1, p1), repeat from *
Row 3: purl
Row 4: *(p1, wyib sl1), repeat from *
Maybe what's tripping you up is the slip sts. They're slipped as if to purl, which means you insert the needle as if to purl, however the yarn is in back. So you have to p1, move the yarn back, slip, move the yarn to front, p1, and so on. It would be just like doing p1 k1 except you slip the st instead of knitting it.
sue- knitting heretic