skipped stitches

[yoshimibattles.livejournal.com]

I'm making a shirt that is knit, and my machine keeps on skipping stitches. I'm using a knit needle and the reccommended presser foot. It's VERY discouraging. At this point, I've adjusted the 'foot pressure wheel', used every different stitch I can think of, and nothing seems to be working. I was wondering if any of you girls might be able to help me out. My machine is an Elna 6300. It's relatively new, maybe 2 years old, so I doubt that it's something I'd have to take it in for.
Thanks, you guys.