Some of the older coated (not silicone impregnated) fabrics I have here are a bit on the gummy side, so I'm pretty watchful if I use them - and usually I save that fabric for 'expendable' projects - not the important stuff.
Sewing is like any other manual skill I've learned - it takes experience to know when the problem is with your tools (not adjusted, not sharp, not tuned up) or with your hands and technique. It's tough to learn on your own, particularly when your tools may not be tuned up properly.
OT (from woodworking)- Once you are handed a really sharp plane or chisel to work with, you will know forevermore when your tools need sharpening. Same thing with a sewing machine - Ironfish knew from experience that he had a machine problem and found the solution.