The BT3 usb thumbdrive bootable I created will not boot from my desktop pc. Just a blank screen saying "Boot Error"

However, it WILL boot on a different pc (laptop), and a different bootable usb distro (knoppix 5.1) booted fine on this deskop pc using the same usb port and same model of thumbdrive.

I get the same result with 4 different brands of USB thumbdrives so it must not have to do with the thumbdrive itself, especially since the knoppix 5.1 DOES boot off the same model of thumbdrive (and yes I ran bootinst.bat correctly). I'm sure it has to do with an incompatibilty between this PC and something about the BT3 configuration.

Is there anything I can try as a workaround?