AZKat,
We use a Wrights Sidewinder bobbin winder. It works great. We've used it on every machine that it fill bobbins for and never had a problem.
I'm unfamiliar with the Singer winder, so I can't give you any advice. Did it come with instructions?
And, why is it your machines won't sew with bobbins wound with machine? Is it tension problems or ... ?
To use ours all we do is put a spool of thread on the spool peg, run the thread through the guide to the tension, around the tension to the bobbin. There is a little flipper switch that controls when the winder shuts off so all we do is push the start button and wait for it to do it's thing.
Joe