I spent years fighting my sewing machine, thinking all the problems were my incompetence because I am the one incompetent in a family with four generations (including DD) of brilliant needlewomen.
Finally having bought some expensive curtaining material I decided to have the machine serviced and in good order before I made the curtains. Turned out it wasnt me at all. My machine was about 35 years old and in my particular model there was a unreplaceable plastic part that tended to crack with age - and it had and caused all my problems.
Two weeks and a new Janome sewing machine (DD recommendation) later I discovered my inner sewing woman. My Grandmother, mother, aunt and sister always used to point out my sewing errors and mistakes, DD encourages me I now have regular sewing days at home, mainly making curtains, repairs and small home furnishings and tomorrow I am off on a quilting and patchwork course.