Proliant ML 110 G6 Boot Device Order Won't Stick

[Allison-R66]

New ML110 G6 server just installed for client.  Server has a P210/256 Smart Array Controller with three 500 GB drives in a RAID 5 config.  Customer has a 250 GB Seagate FreeAgent Go connected via USB that is used for backup.  Server was restarted following some Microsoft updates and did not reboot.  Entered BIOS using F10, raised the boot priority of the Smart Array Controller above the USB drive,saved and everything booted fine.  Shut server down and powered 
back up to test - everything worked fine.  Microsoft pushed more updates and the server restarted automatically.  The server tried to boot to the Seagate and not the Smart Array.  Went back into the BIOS and settings were the same as before I made the priority change.  This time, I disabled the Seagate as a boot 
device and saved the changes.  I brought the server the rest of the way up, then shut it down and restarted.  It worked fine. The next day, same exact scenario.  If we disconnect the Seagate USB drive from the server, it boots fine.  We have since changed the Microsoft Update settings to download only, but that's only a band-aid approach for the time-being. 

Any and all suggestions are appreciated. 

[Graeme_Evans]

Look for the BIOS setting "USB Device Boot Priority"

possibly locate here:

Advanced->USB Configuration->USB Device Boot Priority

Change it from High to Low