Glad to hear it, I've never had to deal with Lee on any warrenty issues, but then I've never sent anything back to them before.
I don't know if I've got the same die as you or not, but mine takes .454 with no problem? I haven't checked, but the seater for my 45acp is probably only for .452. In any even I love the lee dies, let us know how Lee takes care of it.