Motherboard USB problems?

[#1]

Desktop machine with GigaByte G31M-2SL motherboard dual booting under Vista and Win 7.  Various peripherals (Printer, CD burner, Logitech mouse all USB connected and working perfectly.  Up until yesterday I also was able to sync my IPOD on both systems, and connect a Sony digital camera.  Had a reorganise of the desk, replugging everything, and today IPOD and cameras get a "Cannot install drivers" error, and device manager shows Malfunctioning Device in the USB stack on both Vista and Win 7.
I have since sucessfully synched the IPOD on an XP laptop. 
Sounds to me as if the USB controller is packing up?  but why do the mouse, printer and CD keep working.  Is it a new motherboard job, or would a PCI USB card solve it?

[#2]

Try switching the USB ports perhaps? Are there any free ports on the back of the motherboard that you could plug the hub into? Also, if it is a powered USB hub, did you plug that back in after the move around?
Apologies for the basic question, but sometimes these things are the hardest to spot.

[#3]

Orbrey.  Thanks for that - Yes, I've tried all the combinations of the four back panel ports and the two front panel ones with the same result.  Hub is unpowered.  This morning after a reboot, the system sat connecting and disconnecting USB devices (according to the system sounds "bom bah - bah bom")  for about ten minutes.  Now can't connect a memory stick (tried 2 different ones)either - same error "Device driver failed to install"  - both sticks work on the laptop.
Can't think of anything else to try, so I guess it's either a new mobo or a PCI USB controller.

[#4]

Before you go spending anything I'd check if it's software - best way would probably be to use a live linux distro or something, if that detects the usb and it works then it's the software in XP. Not sure how you'd go about uninstalling and reinstalling those short of reinstalling windows, but it might save you the price of the motherboard (or a PCI card). I know it's the same in vista and win 7, but it might be worth a go if you have a disk around somewhere.

[#5]

Solved it.  Definately hardware. Motherboard USB controller is no longer supplying a decent voltage to the bus, hence non-powered connected devices fail.  Borrowed a powered hub, and immediately all is sweetness and light.
As to why it has happened - that remains a mystery probably not worth pursuing.
Thak's for the help.

[#6]

I would hazard a guess that all those devices were drawing more current than the motherboard/power supply could handle. There are limits.