"There is also the phenomenon of spring shock where while tuning the whole bridge just keeps raising and raising, this touches on it somewhat.
Ibanez' instructions on tuning [picking up after the instructions for changing strings] typed verbatim from the Ibanez "How to tune your floating tremolo system"
"There is a trick to it at this stage. With both non-tremolo and 'vintage' tremolo guitars you can bring each string to pitch independently of the other strings. This is not so with a floating tremolo! Though each saddle is separate from the others, they are all mounted together on a single, large plate. In order to get your strings evenly in tune, you will need to tune in "stages". What we mean by this is this: start with the low E string. Turn the tuner until the string is no longer slack, and then move on to the A string. Do this with all the strings. Remember, you're not trying to achieve any type of tuning yet - you're just pulling up all the slack. After this is done, begin with the low E again, and turn the tuner about half a turn, then move to the A string. Do this to all the strings. Then repeat it. Check yourself with a tuner. Eventually, you will get close to being in tune. When everything is close, go ahead and finesse your tuners so they are in tune. *Why is this lengthy process necessary,* you might ask, *and why can't I just tune normally?* Good question! The answer is that attempting to tune "normally" will result in a tremolo unit that has pulled up from the body to such an extent that the action is now about half an inch high, and totally unplayable. Doing it this way will keep your action low and tremolo in the right place."
If you already screwed up and the tail of your bridge is sticking way up in the air with the action 1/2" off the fretboard the only sure way to cure it is to crank in on the trem springs and start backing down the tuning. Be prepared for a real pain in the ass because as the springs adjust to the tension then you'll have to readjust them and retune the guitar, over and over until they settle [when they stop pulling the strings sharp or flat as they adjust].
Of course I cheat quit a bit when I work on guitars, I have a feel for what I can get away with, but every now and then I used to get the trem all whacked out and slacking the strings and a few hours rest before starting again is the answer to getting it back in order but I'll usually just plug forward cranking on the springs until they're way too tight and then backing them off as they start reacting pulling the strings sharper and sharper, all the while I'm constantly tuning the tuners. It's a mess, a real pain, takes forever, tough, deal with it, just get it done!
I only restring a guitar with the bridge blocked to it's full forward position now. When I take the slack out of the strings and unblock I'm usually far too sharp and have to detune into correct pitch. I've NEVER had string shock working this way and highly recommend it."
-Rich Harris @ Ibanezrules.com