Perhaps the new ones are rubbish, and maybe the last 10 Fenders i owned had the better ones fitted because i have never had a problem. Except with the GT Toronado tuners (that are'nt Klusons anyway).
What year is your Jag and are you positive it is fitted with the new tuners?
Oh, i would'nt get too worked up about what people say is gospel on forums either. If they work okay for you thats all that matters.
To hear some people talk buying a CIJ is a waste of money. 🙄