I've not had issues with bowing but I'd suggest following the other suggestions of alternating your sewing directions. You might also want to lengthen your stitch length a tad. I'd think too short a stitch length would add to the problem. Not sure I'd adjust tension if your stitches are performing correctly. Try making just one adjustment at a time to see where the problem might really be. If you change everything at once you'll have a harder time correcting any given issue because you won't know where to start!