I have owned a couple fixed-bridge Carvins for many years now, and keep finding myself having difficulties getting a perfect setup without fretbuzz. After a lot of double checking my work and tons of patience, I've come to realize that my nuts are wearing down. My strings are sitting slightly below the summit of the nut, especially the treble strings. I feel it is strange that is happening because I don't do a lot of string-bending, but I suppose my frequent re-tuning and de-tuning is the culprit. I am going to order a couple replacements soon, (both have been TUSQ in the past, any reason I shouldn't keep buying them?" and am wondering if you guys feel any nut lubricants would help with this issue? I had previously been advised to use Stewmac Guitar Grease when my Wilkinson-equipped Carvin (no locking nut obviously) kept going out of tune, but never thought I'd need it for my fixed bridge guitars. How do you guys feel? Do I just need to change out the nuts on a regular basis, or can lubrication help?