Originally Posted by AndiR
Is the needle in the right way and all the way up in the needlebar?
Is the needle too small?
Are you moving the fabric too fast for the speed you are running the machine?
What type of foot do you have on? I once purchased a large diameter hopping foot for my machine, it apparently did not give enough pressure on the quilt sandwich so I was having skipped stitches. Went back to the small diameter one and it solved the problem.
Hope you get it figured out soon!
2 thoughts occurred to me while reading this - Singer needles are longer, so if you are sewing on a Singer and not using Singer needles, this could be a problem. Also, some machines have a presser foot adjustment - you can adjust how much downward pressure the foot will exert on the fabric.