I connot get any of the bonus content of the GOTY edition to install.
Every time I insert the disk it starts up and says this:

You must have a hard drive to install this
expansion pack. Attatch an Xbox 360 Hard
Drive and try again.

Then when I press OK it just takes me back to the dashboard.
I am using a semi-new Xbox slim (about 9 months old)
If anyone knows how to fix this please respond.