This might save someone a good deal of sifting through ancient posts on obscure forums: if you wonder why your SunBlade 1000 workstation refuses to boot off a freshly burned DVD, keep in mind that the standard-issue DVD drive in those machines (typically Toshiba SD-M1401) is pretty picky about the DVD media type used. Trying to boot off DVD-R discs invariably failed for me with a "read failed" error, while the same image burned onto a DVD+R blank worked like a charm.