hey rainonthegrave. here is my take on what could be wrong.
1) if your tremolo is ****-eyed, it'll bind and cause it to not return properly. i just had this happen. i turned one stud like 1/4 turn and it took care of it. it had a nice bounce and everything. tap on the trem itself and you should feel a slight "bounce". thats how you'll know that both studs are level.
2) your studs are worn or knife edges worn.
3)also check your
locking nut and be sure those two screws are snug. they will loosen up over time. as a matter of fact, i would check the
neck bolts and even the saddle adjustment screws. they all loosen up with time.
tremolo: i would replace it with an Original Floyd Rose. Or an edge if you want to remove some wood.
keep us posted