My fretless is buzzing in the area around the 9th-12th "frets". This is the neck that came on my SX a long time ago, and I remember having the action really really low and having lots of mwah with no harsh buzz. Then I bought a fretted neck and put that on there for a while. The other day, I put this fretless neck back on there, and now it buzzes in the previously mentioned spot. I've tweaked around with the relief and with the action, and nothing can cure it. It does get better with more relief, and does go away with super high action. I don't want super high action though, so I'm not satisfied with that remedy. While being stored, I did have the truss rod loosened like it should be. When I eye ball the neck, it looks like it should, with no major warping... just the usual relief (based upon truss rod) in the usual position. Any ideas on what to do? Should I try sanding the whole thing down a little bit? Where can I get a radius block?