A challange

This one has me stumped big time, i have an ABIT AI7 spec as follows:
3.2ghz P4
512mb RAM
CD + DVD RW on IDE1
Nothing on IDE2
SATA 250GB (x2) drives on Mirrored RAID

The post is as expected, goes through pretty much reports what ive just said, next it goes to the RAID controll utility with the option to enter it, ignored it continues, displayed IRQ's etc and goes to boot, as instructed, from hard drive (i have no other boot devices in the boot menu of the bios, primary is hard drive, the rest are disabled) it however instead of going directly to the SATA array it looks at ALL the onboard USB ports and treats anything with storage plugged into one as a bootable disk and flashes error (as id expect) 'Not a bootable Disk, insert a bootable Disk and press any key'

What confuses me is why is it even looking at USB let alone trying to boot to it, primary boot is to the hard drive, am i being dense to assume it would only go there?

Remove the USB device (from a USB key to a card reader with a card in it) press any key and it boots to Windows XP. Would any of you guys have any clue on how to fix this?

I have several USB devices always plugged in and it is a mission to unplug them every time i boot up!

 

Ya might check Abit's Web see if any Bios Update applies,
I'm thinking Version 16
http://www.abit-usa.com/downloads/bios/bios_revision.php?categories=1&model=147