Hi All,
Nice to meet you all S Series users. I am having S470 and i have been playing it since last one year. When buying i adjusted the string height very well. The Ibanez trained guy adjusted the fret bar and also the tremolo unit to suit my need.
That guy installed 0.009-0.042 string and warned me to use this set only. But after one year of using, three days back i found the string height was no more comfortable enough to play. So i tried to adjust string action by TIGHTENing (i think so) the truss rod which worked no doubt. But during my playing i observed two things -
1) in the middle part of the fret bar (from 8 fret to 13th fret) the string height is still higher compared to higher or lower frets.
2) the lower strings, specially, 5th and 6th (E and A) strings height is quite higher compared to the higher strings (1st, 2nd).
As far as the point one is considered, i think a little more turn in the truss rod will solve the problem and i will get a smooth string height all over the fret bar. But yesterday i stopped as suddenly i heard a cracking sound

(i hope my guitar is still good and nothing happened from inside).
Should i proceed any further and is this the stopping point 
or it is a natural phenomenon ? (<- My first question)
And for point no 2 -> i think by adjusting the tremolo unit will lower the lower string heights.
But how do i do it? (<- My second question). As i found only a screw nut (referring to Fig 3 B of 2008 user manual) which can be loosened or tightened,
but how do make the unit go up or down 
?
If there is any other way please suggest!
Cheers and happy guitaring,
Nabarun.