I recently bought a set BC Racing adjustable coilovers. I was under the naive impression that you removed the old set up, bolted these on, and adjusted the height by simply turning the adjustable locking nuts. Wrong.
It appears that you also have to unbolt the bottom bolts of the coilovers (so the coilover body itself can turn), adjust the locking nut, re-bolt them at the bottom again and retighten the locking nut. Which basically means you could end up doing this several times until you achieve the desired height your after.
Does this sound right?