Sorry, flax, but this idea of never removing all the strings, or changing them in a particular order, is bogus, and it pains me every time I hear it.
No offense intended (honest). I have taken off all the strings at once - in the process of doing my bridge block experiments, or oiling the wood - on the order of 30 times in the last year, with no ill effects.
Back at the 'mother ship', they do this for any number of reasons - like leveling a fingerboard, doing fretwork, and so forth - and the only special consideration is that if the strings will be off for a significant period of time (several days or more), then they will loosen the truss rods a little to keep things at ease.
paulembic - just to be sure I understand what you're saying, it looks to you like the heavy-string side of the neck bulges up towards the strings, rather than having a small amount of relief. If so, then you should tighten the the truss rod on that side, i.e. turn the nut clockwise when looking at it from the bridge.
Normally I'd start with only about 1/8 turn, but if you can visibly see the problem, start with 1/4. Gently(!) twist and bend the neck slightly in the desired direction for a minute or so, to help it settle, then retune and see how it goes.
Good luck, man.
[edit: what a bozo - I said it backwards here, and then again a couple posts below. If the neck is concave, tighten the nuts. Sorry.]
(Message edited by bob on April 07, 2005)
