I have discovered a tension issue with my knitting and I can't figure it out.

The deal is: When I switch from knitting to purling, there is an excess amount of yarn used in the process. It is most noticable in k2p2 ribbing when all the leftmost stiches in each knit column are larger than the others. I'm finding it also shows up in my cables.

I hold my yarn in my right hand and I suspect this has something to do with my trouble.

For now, I am wrapping that first purl stitch tightly in the wrong direction and this helps, but it's annoying.

Does anyone else have this problem?