Looks as tho you are correct.
Supposedly you can boot bios from a Thumb drive http://www.msi.com/index.php?func=te...&express_no=81
I don't think you can as I believe that the jmicron is just for raid configurations.
Reading some of the information on M-Flash, it looks like I can boot from a USB/Floppy to try out the new BIOS first before flashing it. I'll be trying that next time. Maybe it has issues with the newer AMD 955 proc?