In fact if I look at the real ISO image there is a link there:
apw@dm$ ls -l /mnt/dists total 2 dr-xr-xr-x 4 root root 2048 2009-02-08 07:32 jaunty lr-xr-xr-x 1 root root 6 2009-02-08 07:32 stable -> jaunty lr-xr-xr-x 1 root root 6 2009-02-08 07:32 unstable -> jaunty
So this looks like a bug in usb-creator rather than in the image or the script.
In fact if I look at the real ISO image there is a link there:
apw@dm$ ls -l /mnt/dists
total 2
dr-xr-xr-x 4 root root 2048 2009-02-08 07:32 jaunty
lr-xr-xr-x 1 root root 6 2009-02-08 07:32 stable -> jaunty
lr-xr-xr-x 1 root root 6 2009-02-08 07:32 unstable -> jaunty
So this looks like a bug in usb-creator rather than in the image or the script.