If it's correct or not, I don't know, but on all my cars, whenever I've changed suspension, I've never bought new nuts. Always been happy with the nuts I've had. And my nuts have never given me any problems.
Changed the suspension of the celica 3 times, and still using the same nuts.
Have you cleaned your nuts?
(no, that has nothing to do with it - I just needed some excuse to work inn more nut-referals