first sergeant's lady

I Need Help!!! I purchased my nolting funquilter from a quilt show in July. I am ready to send it back! I have used about 30 yards of fabric for practice trying to adjust the stitches, the tension and just learn the feel of the machine. I have called and emailed the company, calling I get a better response. They say I need to adjust the tension with every quilt, different fabric and batting makes a big difference. Really? But the machine is still not what I expected to have in a long arm. The tension is not right. I can go straight and the tension is fine, but when I make a curve or a circle - anything but straight - the bobbin thread comes up and loops, and the top thread goes really tight. Obviously a tension issue, except why does it do fine if I go straight, why on curves? The nearest Nolting quilt instructor who has agreed to help me is five hours from where I live. It might be a great machine - but without support I can't see it as being my dream. Is this my problem because I don't make the machine go slow enough or fast enough? I am winding my bobbins on my Bernina - is that a problem? Am I not using the stitch regulator right? Biggest question of all - should I go back to hand quilting? Is this the learning curve? What can I do? Any advise is appreciated.