Take the clamps off the lock nut, stretch the strings out and keep re-tuning to pitch, make sure the nut mounting screws are tight, and that the neck mounting screws are tight. Make sure all the Floyd screws are tight (saddle intonation and the string lock screws the fine tuners act on). When you have all that done, put the fine tuners in the middle of their travel, re-tune to pitch with the tuning machines, lock down the clamps, and then fine tune. ALWAYS come UP to pitch on the tuners...if the note is sharp, go below it with the pegs, come back up, give the string a tug, come up again, until you're in the sweet spot. Then lock down the lock nut and fine tune.