Hey nygal,
See this post I made a while back, it should help you out with your tension gremlins, and adjusting the bobbin case tension.
http://www.quiltingboard.com/vintage...g-t195869.html
Once you know that the bottom is right, you can set the top per Singer's instructions in the manual and you should have a great starting point (i.e. set to factory settings) to work from.