It looks to me like you have built a second drive, bigger than 40G, using the original builder image, and then cabled it in as slave.

When you add content to your player, the player distributes it across the disks it has available, and then records the meta data (tags, name, location etc) in the static database.

If you have simply shoved a new disk in in place of a dead second drive, it is now complaining that it can't find the tracks it expected to be there (from the old one).

You need to build this disk by hand using the instructions on Roger's website (www.differentpla.net) instead of using the builder. This will take a bit of command line magic using an installed developer image. You will then have to re-build the track database, which you can find in the FAQ.