Summary: Got a new motherboard, a Gigabyte 970A-D3 Rev 3.0, and USB and networking no longer work with 64-bit Ubuntu. Everything else works; USB and Networking DO work with 32-bit Ubuntu. I'm suspecting a bug in the 64-bit kernel but not sure how to proceed.

In a little more detail: When I boot my computer with the live Xubuntu 12.10 32 bit DVD, everything works fine. USB devices are recognized and work perfectly. My network comes up and gets configured via NetworkManager/DHCP automatically. No problems.

I can take the USB devices out, put them on different ports...no problem, they work as they should. For the network, I've tried using my built-in Ethernet port and a PCI Ethernet card. With the 32 bit distro, both work fine and automatically.

When I boot my computer with the Xubuntu 12.10 64 bit DVD, however: USB and Networking DO NOT work. Same devices, same USB ports, same cables, everything the same... but no USB, and no network.

For the network, both Ethernet interfaces are recognized and set up by the OS, so ifconfig shows eth0 and eth1 (or just eth0 if I take out the Ethernet pci card). But they can't actually connect to the network. The cable is plugged in, the lights are on, everything is the same as it was minutes ago when the SAME DISTRO, just the 32-bit version, did it correctly...but now, no dice. The hardware is recognized the same with lscpi under both 32 and 64 bit versions; the same modules are loaded. I've tried disabling network-manager and setting up the interfaces manually, but it still doesn't work (for the 64bit version).

For the USB devices, again. they same devices that worked just seconds earlier with the 32-bit OS are now dead. Not listed in lsusb (the usb ports are there, but empty, no devices recognized). In the dmesg logs, the errors are a bunch of lines of this sort:

usb 4-1: >new full-speed USB device number 2 using ohci_hcd
usb 4-1: >device descriptor read/64, error -32
usb 4-1: >device descriptor read/64, error -32
usb 4-1: >new full-speed USB device number 3 using ohci_hcd
usb 4-1: >device descriptor read/64, error -32
usb 4-1: >device descriptor read/64, error -32
usb 4-1: >new full-speed USB device number 4 using ohci_hcd
usb 4-1: >device not accepting address 4, error -32
usb 4-1: >new full-speed USB device number 5 using ohci_hcd
usb 4-1: >device not accepting address 5, error -32
hub 4-0:1.0: >unable to enumerate USB device on port 1

(sometimes its ehci_hcd depending on the port used)

Googling around for similar errors, most people who encounter this USB error message end up having had a hardware problem--a shaky connection or bad cable, etc. That's not the case here, since the same devices work perfectly with the 32-bit version of the OS.

I've gone ahead and tested the computer with a bunch of different distros, to see what results I get.

Xubunutu 12.10 64bit ..... NO
Kubuntu 8.04, 64bit ..... NO
Linux Mint 14, 64bit ..... NO
Fedora 18, 64bit ..... NO
MarBSD (openBSD), 64bit ... YES
Xubunutu 12.10 32bit ..... YES
Knoppix 7.05, 32bit ..... YES
Fedora 18, 32bit ..... YES

NO = No USB or Networking, otherwise works OK
YES= USB, Networking, and everything works OK

In other words, the 64-bit Linuxes all fail, the 32-bit all succeed. Noteably, the 64-bit BSD also works.

The only thing I can think of is that there is a bug in the 64-bit Linux kernel and/or modules or drivers that come with it, that prevent it from working with my motherboard (which is a Gigabyte 970A-D3 Rev 3.0, as I mentioned). Unless I'm missing something.

I'm not sure if there are changes I should try making to the BIOS settings, or boot parameters, or something else.

Or should I give up and get a new type of motherboard?

Any ideas on how to proceed?