barry, i have a theory and i've ran it across a couple other folks who make strings. the material, nomatter what it is,only has so much creep to it, and its no where near the elongation some folks end up experiencing. certain manufacturers tie no knots in the tag ends of the string. if there were a knot you'd see it somewhere under the serving. i think that every time the bow is shot the string is actually sliding apart under the serving - that the tag ends are getting pulled on little by little making the string and cables longer. that's what i believe anyway. its why i serve my loops with the tag ends of the string and then serve over them at the ends. there is no way its going to slide apart. basically if i get a customer who says a cable won'tstay put- then i know for a fact there is a problem with it because i've taken so many precautions against that happening. anyway, the fellow above said it was the material - and that's what most folks think. d75 has a lot of creep, i'll agree to that, but it doesn't take much to get it all out, and it should stop creeping pretty quick - even if it wasn't stretched or served under tension. so i'm just throwing my 2 cents in as to the reason.