Hey. A little over a week ago, I finished tweaking the setup of my MIM Jazz. I'm no pro at that, but I got it a hell of a lot better than it was before without spending my money at the local store. Farely low, but with a little buzzing in the upper frets unless I played obscenely light. It stayed this way for several days. Then I left school for break and came back about a week later, and it was back to its old ways of high action. Is it normal for a neck to shift a lot like this in the course of a week? If it keeps doing this, what should I do- get lighter tension strings? (I was planning on trying out Thomastik-Infield Jazz Rounds at some point anyway).