Hi Nicolai,

saying you have adjusted the nut to the point of approaching the end of the rod suggests an intact rod, especially if the rod wasn't rattling before loosening it. Looks like you have a back-bowed neck, there can be loads of reasons for that - I'm sure Stephen can supply you with all of them - off the top of my head possibles are: the wood of the neck swelling; strings losing tension causing the rod to have a greater effect on the neck; changes from heavier gauge to lighter without adjusting the action; or a combination of all, especially if it has been in the case for a number of years.

If Stephen confirms that it is back-bowed and the rod is ok, I would never visit those guitar shop "luthiers" again as, I suspect, a genuine luthier would spot the problem within a few minutes (for info, I'm not a luthier so could be talking rubbish).

I've sucessfully heat treated one of my fenders that was back bowed but only because it was cheap and I was willing to take the hit if I broke it, I could buy and fit a cheap 2nd hand one if it did break. If it was valuable to me I would have taken it to a genuine luthier to fix.

Fitting heavier gauge strings (12's or 13's perhaps) might help.

Best of luck.

Cheers,

Gordon