Okay, so I've installed a shimano cassette on my new set of wheels and torque'd the lock ring to the specified 40 Nm and there is a bit of play between the cogs. The only ones that do not move are the largest three (they're joined together) and the smallest one. The rest of the cogs have a bit of wriggle room and make a bit of noise when you shake the wheel. Is this normal? If not, what could cause this? I've used all of the spacers and followed the instructions as far as I know.