Hi again Mac,
Unfortunately I wasn't able to reproduce that crash on any of my systems -- it's a head-scratcher.
Anyway, I've created this image that has the ACPI power management code disabled, so this should allow you to test USB connectivity on your system: http://visopsys.org/files/misc/partlogic-2011-08-29-iso.zip
Even since our last messages, I've done more work on USB. Currently, every USB peripheral that I have access to, works - though hot-plugging some USB disks is still a bit hit-or-miss (I'm working on that!)