A true mystery! If the drive is bootable on other PCs then it could be something non-standard with your laptop's BIOS I guess. Or even a bug. Did you check to see if there's a BIOS update for it?
Looking at your screenshots, that Fast/Normal boot setting seems like it could have something to do with it. What happens if you set it to fast?
What you can do in the meantime is install Chameleon to a USB flash drive and boot from that. Well, hopefully that will work. I know it's not very practical but at least you can unplug it once you're done booting.
EDIT.. oh wait, you tried that already. Try changing the "SATA Interface" setting. A wild guess, probably won't change anything.
You can also try setting a password for HDD1. Yes I know it sounds weird, but I remember reading something about that setting having an effect on the ability to boot OS X on a PC. Actually, just carpet bomb it, try setting passwords for everything there and see if it makes any difference.
If that doesn't change anything, try something else, for troubleshooting purposes:
Find the "HP USB Disk Storage Format Tool" with google. Run it on a Windows PC and use it to format your flash drive as a bootable DOS disk. You will need MS DOS boot files as well, some of the tutorials for the HP USB tool that you can find with google will have a link to these. I would attach them here for you but I don't think it's legal.
Now try booting your laptop from that, just to see if it can successfully boot into DOS off of the flash drive. Let me know what happens. If it works I might have an idea what you can try next.