Are you running the most current BIOS?
The USB boot priority set-up option is design to place USB disks at the top of the boot order any time a new USB disk is detected.
If you disable this setting, a new USB disk would be placed at the bottom were it won't impact anything.
I am guessing that since you did disable it:
I have gone in to the BIOS and removed all devices from the boot order besides the internal RAID, all the options to boot off USB/removable devices are disabled.
You later remove the USB drive and reinstall it which the system see as a new device being added.
I will try to update the bios.
It seems intel's site is busted as i get page can't be displayed when i try to download the windows bios updater, i have a msg in to them to fix that.
I did disable the usb boot option, so it shouldn't be adding anything, and if i check the boot order even after it "freezes" due to usb being connected, the usb drive isn't listed in the boot order.
Basically, we swap out external drives for backups so we're removing and adding "new" drives on a daily basis.
thanks for your help.
Seems to be working now.
One Flash Update version http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=18060&ProdId=2487&lang=eng
( I had some strange error earlier also. )
(To err is human, to really mess up your day, requires a computer.)
Is it any USB drive that gives you problems or just a specific drive?
(I seem to recall reading something about USB 1.0 drive devices not playing well, but can't find the reference now.)