demo disk dunce

When ever I try to record samples or tracks onto the demo disk I'm met with a "disk protected" message, or I'm told there isn't enough space.
Are the phrase samples supplied with the disk simply for playback and demo purposes, or is there a way to use them in a recordable composition?
I imagine I'm doing something wrong, if someone would point me in the right direction I'd appreciate it.

Thanks,
circlehead*

P.S.
Is there anyway to see how much space is left on a disk while in the 808?