button hole problem

[lovepink0099.livejournal.com]

I am making my husband's halloween costume and I am trying to put button holes on it. I have a Janome machine with an automatic button-hole feature. However, when I make the button hole, the stitch density is different on the left and right sides. The left side (where the machine sews backwards) looks nice and the stitches are thick and close together but on the right side(where the machine sews forward) the stitches are farther apart like a zig-zag stitch. I have adjusted all the dials on my machine but I can't figure out how to make them the same. Does anyone know how to fix this problem?