USB switches to Unknown; from IRQ ?

[Chet]

An update on my previous posts (orig: Scanner not recog.)

1. XP Pro: USB devices not recognized. All Unknown.
2. Restart in Safe Mode. Recognized here.
3. Delete Root Hubs and USB Controllers in Safe Mode.
4. Restart from Safe Mode. All USBs now recognized.
5. Restart again, and they go back to Unknown.

What I've noticed is that in steps, 2 and 4, the IRQ for
the VIA Host Controllers are set to '5'. In step 5, they
are set to '11'. I notice there is also a ethernet pci
card with '11' as well. Everything indicates all is
working with no conflicts. Is this the main cause of my
problem then? If so, why is it changing? I can't change
the IRQs myself, due to article>
http://support.microsoft.com/default.aspx?scid=kb;en-
us;314088&Product=winxp

Any suggestions on how to proceed?
Thanks,
Chet

PS. I may also try removing SP1 to see if that works, per
Dean's post.

 

[Chet]

Post correction:

After duplicating my testcase again, and reviewing
settings while USB was working, it turns out that when
the USBs are set to IRQ '5', that ethernet PCI was also
set to '5'. When I restart, in step 5, they all go back
to '11', and the USBs are unknown again.