Booting a Thinkpad T23

I'm trying into install OpenBSD 4.0 onto my laptop.  It's a Pentium 3 1.13 MHz with 768MB RAM.  

I burned an install CD following the installation instructions.  I burned the cd40.iso first, started a multisession CD.  Then afterwards, burned the rest of the packages and finished the multisession CD.  This setup boots fine on my desktop system.

On my laptop, however, it reads the CD, but it does not boot, and goes straight into the hard disk boot (Lilo in my case).

I've tried disabling hard drive boot, enabling the floppy disk, enabling superdisk boot, updated the BIOS to the latest release, and even burned another CD with the cdemu40.iso, all to no avail.

Does anyone know how I can boot onto my Thinkpad?  Any help would be greatly appreciated. :)