As others mentioned, pattern is a little unclear sometimes.

Some notes:
Row 9: K4, increase, *k2, increase*, k4
…would be less confusing, as the last stitch before the garter border is another increase (This applies to all increase rounds)

Sleeves

You have 4 markers. The 2 two sections with the garter band on the sides are the front of the cardigan, the largest section is the back and the other two sections are the sleeves.
I would recommend putting them on scrap yarn on the next r.s. where you have to cast on the additional stitches.
-> knit to marker, put all sts inbetween markers on hold, cast on 4 ( I used the backwards loop method) and so on.

These 4 will be part of the body as well as part of the sleeves as you pick them up later. (like you do, when you knit thumbs on gloves)

Buttonholes

in size S -> rows 3, 23, 43, 63, 83

The End

Row 74: as row 10
75: k all
76: as row 12
77-80 stockinette with garter bands
81-82 k all
83: k all, buttonhole
84-85 k all, bind-off

All the yarns used were left-overs or already in stash.

13/02/2013: Knitting part is done - still have to attach the buttons and weave in some lose ends.

14/02/2013: Done. Now I hate attaching buttons.
The colors are hard to photograph.

Edit: I have been told that the cardigan fits perfectly! Yay me! Yay pattern!