Expert Help Required for USB problem

Cannot fathom this one out at all, but if you think you know how to
resolve this one I would be immensely grateful....
The USB ports front and back and the Memory stick slot no longer work I
believe it must be a BIOS problem but am open to suggestions

The hardware:
A Sony Vaio Desktop (PCV-RS404) running Windows XP (SP1)
I have reset it to factory defaults, except the BIOS which is the
latest version 1005

When I plug in a Casio camera or an HP scanner to the front or back USB
slots I get nothing. However the Device manager shows 4 USB port
controllers working fine. When I connect the Casio camera, the camera
itself says its connected to the USB port.

I feel I want to roll the BIOS back to check it out but Sony have said
they can't help me do this and I can't find anything yet on the net to
help me do this

Does anyone have the savvy to help with such a problem?....I'm
determined to exhaust all possibilities before handing the machine over
to Sony who are going to charge me £250 for the pleasure of looking at
it

Any help will be gratefully received

Many thanks

Will