lace ribbon scarf - knitting and purling into 2yo's?

[petitghost]

I'm currently knitting this pattern:
http://knitty.com/ISSUEspring08/PATTlaceribbon.html

I'm getting really stuck though. I can do the row with all the increases and decreases, but it's the next one of just knitting and purling thats stumping me. I always seem to end up with the wrong amount of stitches. I think it might be something to do with knitting and purling into the 2yo's on the previous row. It just feels really wrong and almost like I'm not really knitting them sometimes?

Can anyone help me? I love this scarf and I've had to unravel it a ridiculous amount of times already!