The Smart Boot Manager is an open source boot manager written by James Su, Lonius and Christopher Li, which among other things contains a standalone El Torito stack.

If you are cursed with a system on which ISOLINUX simply will not operate, you may want to try to load SBM onto a floppy and then use its "Boot From CD-ROM" feature, which will use SBM's El Torito stack and not the BIOS's.

If you encounter this on a new system, don't forget to complain loudly to your vendor and/or obtain a BIOS upgrade.