Vista - BSOD USBHUB.sys on shutdown

G'morning all,
I have a Dell M-90 laptop, with Vista Business (version 6000) running. Have
the dualcore 2.16 ghz processor, 4 gigs ram installed.

after a MS update about 2 months ago, on shutdown, EVERYTIME, it get the
blue screen of death, pointing to error 0x000007e, USBHUB.sys.

I've reinstalled video drivers (several times), un/reinstalled pci bus, held
my tongue out, and Dell even replaced the motherboard on the computer, all to
no avail.

Any suggestions, hints, voodoo would be greatly appreciated