Thanks for your comments, but the problem on my system is not with the CD drives nor with the USB or bios, as I can boot other systems with both cds and USBs. The problem is in the software, apparently casper, as older versions of k/ubuntu (8.10 for example) boot as they should. The newer live-cd, cd and USB installer versions of debian based systems (sidux, x/l/k/ubuntu, and even the newest lenny) are what do not boot; opensuse-11.2 does boot, from either cd or USB.
Thanks for your comments, but the problem on my system is not with the CD drives nor with the USB or bios, as I can boot other systems with both cds and USBs. The problem is in the software, apparently casper, as older versions of k/ubuntu (8.10 for example) boot as they should. The newer live-cd, cd and USB installer versions of debian based systems (sidux, x/l/k/ubuntu, and even the newest lenny) are what do not boot; opensuse-11.2 does boot, from either cd or USB.