I downloaded the 2007.0 LiveCD from http://gentoo.mirrors.tds.net/pub/gentoo//releases/x86/2007.0/livecd/livecd-i686-installer-2007.0.iso When I tried to burn it, I discovered that the image is 700.3 MB, which is just a hair too large to fit on a CD. I used overburn to do it anyway. When the BIOS finds the bootable CD, it tries to load the boot menu but fails with: ISOLINUX 3.09 2005-06-17 Copyright (C) 1994-2005 H. Peter Anvin isolinux: Disk error 02, AX=420D, drive 9f Boot failed: press a key to retry... Reproducible: Always Steps to Reproduce: 1. Download livecd-i686-installer-2007.0.iso fails to boot 2. Burn the image, using overburn. 3. Boot from the CD. 4. Add to your coaster collection. Actual Results: Boot menu fails to load. Expected Results: Should load and boot. System: Dell PowerEdge 2400. ATAPI CDROM.
There's not much we can do about the fact that your burner or media can't reliably use overburn to add that extra 0.3MB. The CD works for almost everyone else. Have you tried using different media or at least verifying the burned image?