You should be able to boot from USB just fine. I'm running 2.04a bios right now, and know it can boot from USB, but I'm pretty sure 1.05 can too.
I have heard (though not verified myself) that you cannot boot past a USB hub... it has to be directly connected to the computer, and some USB devices have built-in hubs, making them impossible to boot.
When you boot up your computer and it is POSTing, it lists all the devices connected to your computer. Does it list your USB device? If so, you should be able to boot from it. I think you may have to go through your BIOS each time you wish to boot from it though.
Try these steps at startup:
Push F2 to enter your BIOS
Go to the BOOT tab
If harddrive has a + on it, it means you can expand it. Click on harddrive.
Harddrive should expand. You should see a list that contains your harddrive and your USB device. Move your USB device above your harddrive.
Exit saving changes.
I don't think it really saves the order past rebooting.. I think you would have to follow those steps every boot from USB, but I'm not sure. If your BIOS doesn't have those options, try searching the forums for a newer BIOS.