Yup, that spacer's there. I was just a little concerned about the noise and the cracking during installation. Good to know it's normal!
Originally Posted by
Al1943
Congratulations, you're done, normal procedure. Go ride it!
edit: You said you have the correct spacers, if the cassette has 10 cogs there should be a spacer approximately 1mm thick at the back of the cassette. This spacer is included with new Shimano cassettes.