Hello,
I too have the problem of a non-bootable Linux.

My System:
Intel Core 2 Duo E6750 2,6GHZ
Corsair 2GB DDR2 RAM
ASUS P5K Mainboard with JMicron Controller
Seagate 500GB 16MB SATA HDD
LG GSA-H62N ATAPI DVD-Writer (SATA?)

I tried:
Knoppix Live CD 5.0.1 --- Can't find file System (including ALL cheatcodes, none of them worked)
Knoppix Live CD 5.1.1 --- Can't find file System (including ALL cheatcodes, none of them worked)
openSuse Live DVD 10.2 --- Can't find CD
openSuse Live CD 10.3 RC2 --- Can't find CD
TING 2007.0-r2 (seemed to work)

I checked the md5sum's (all correct) and the CD's/DVD's are working on other (older) computers.
Only the TING seemed to start correct, but I had no GUI. Since I am fairly new to Linux and have also very limited knowledge of the Gentoo-Live-CD I don't know if there is a GUI anyway...

I want to install SUSE, or Debian, or Gentoo (also Gentoo not in the near future) for research, so I don't want to install a different Linux.
I would appreciate Knoppix as a Rescue-Live System, but after all I can't install any Linux.

Many forums complain about the JMicron-Controller, but the several CD's/DVD's I tried have different kernels, so I'm not sure where the problem really is located here.
Someone knows a solution?

HAVE PHUN!