Hey folks,

I've done as much homework as I could on this issue before posting, so I'll try and include all the necessary details.

First of all, my USB port is in working physical condition. It works under Windows and also worked in Xubuntu 8.10. Once I upgraded to 12.04, I was no longer able to use it. The error given by lsusb was a -99 initialization error for the libusb library.

Upon further investigation with dmesg, I noted the following pertinent information:
ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
ohci_hcd USB 1.1 'Open' Host Controller (OHCI) Driver
uhci_hcd: USB Universal Host Controller Interface driver
uhci_hcd 0000:00:07.2: can't find IRQ for PCI INT D; please try using pci=biosirq
uhci_hcd 0000:00:07.2: Found HC with no IRQ. Check BIOS/PCI 0000:00:07.2 setup!
uhci_hcd 0000:00:07.2: init 0000:00:07.2 fail, -19
usbcore: registered new interface driver libusual

Clearly there is an issue involving ACPI compatibility between my BIOS and Xubuntu 12.04. I have the latest available BIOS firmware, and the setup does not have settings for the USB port or legacy/pnp operating systems, so I'm SOL on that end.

I have tried various combinations of boot options, turning ACPI and APIC on and off, using biosirq and noirq and so on, nothing seems to have hit the spot yet.

I ran lshw and got the following:
*-usb UNCLAIMED
description: USB controller
product 82371AB/EB/MB PIIX4 USB
vendor: Intel Corporation
physical id: 7.2
bus info: pci@0000:00:07.2
version: 01
width: 32 bits
clock: 33MHz
capabilities: uhci
configuration: latency=64
resources: ioport:fcc0(size=32)
*-bridge:1
description: Bridge
product 82371AB/EB/MB PIIX4 ACPI
vendor: Intel Corporation
physical id: 7.3
bus info: pci@0000:00:07.3
version: 02
width: 32 bits
clock: 33MHz
capabilities: bridge
configuration: driver=piix4_smbus latency=0
resources: irq:9

So that's where I'm at, I think all the pieces are there, I'm just hoping someone can help me put them together, being a novice Linux user.

Thanks in advance to anyone who can help!