problem: only 10MB iso file

[UnderScore]

Open up the isolinux.cfg file in a text editor and notice the second line. It is the second line that controls the default bootup behavior.

1: DEFAULT linux24
2: APPEND ramdisk_size=100000 init=/etc/init lang=us apm=power-off vga=791 initrd=minirt24.gz nomce quiet BOOT_IMAGE=knoppix
3: TIMEOUT 300

Add a 2 to the line #2:

1: DEFAULT linux24
2: APPEND ramdisk_size=100000 init=/etc/init lang=us apm=power-off vga=791 initrd=minirt24.gz nomce quiet 2 BOOT_IMAGE=knoppix
3: TIMEOUT 300

Then save it and exit the editor.
Now it should book to runelevel 2 by default.
I hope this helps.
James