my 80 grit belts for my no weld grinder will not track straight. they jump back and forth.my wife got them for me as a surprise from a dealer in town. but only those belts. i purchsed few belts from usa knifemakers and they dont have a problem tracking at all. so my question is does it realy make a differance what brand they are or is it that they are just stiffer than the other belts? or am i doing somthing wrong.