sewing machine problem

There are several reasons why this is happening, one is the needle could be in the machine wrong. Next, check your threading, I have had the problem and found that the machine was threaded wrong. Also check the bobbin and make sure it's in right. You might also need to put a drop of oil in the feed dog area and the bobbin race...but that depends on the age of your sewing machine. Oh, check under the throat plate and make sure that there isn't a build up of lint in the feed dog. I had to go up to a neighbors house because her Bernina wasn't sewing right and I found enough lint in it to knit a sweater. When I pointed it out to her she looked at me with a surprised look on her face and said "Gee, do I have to do that? I didn't know that!". If all of that is okay, then you might need to take the machine in for a tune up. The newer machines need to be serviced more regularly than the older machines.