USB Errors Mounting External HDD

[Simon Andrews <simon.andrews@xxxxxxxxxxx>]

I've got a LaCie 200Gb external USB HDD which I'm trying to use on one 
of our servers.  Unfortunately when I try to connect it I get a load of 
errors and can't access it.  The relevant portions of /var/log/messsages 
are:

kernel: usb 1-2: new full speed USB device using ohci_hcd and address 2
kernel: usb 1-2: device not accepting address 2, error -110
kernel: usb 1-2: new full speed USB device using ohci_hcd and address 4
kernel: usb 1-2: device not accepting address 4, error -110
kernel: usb 1-2: new full speed USB device using ohci_hcd and address 5
kernel: usb 1-2: device not accepting address 5, error -110
kernel: usb 1-2: new full speed USB device using ohci_hcd and address 6
kernel: usb 1-2: device descriptor read/64, error -110
kernel: usb 1-2: device descriptor read/64, error -110
kernel: usb 1-2: new full speed USB device using ohci_hcd and address 7
kernel: usb 1-2: device descriptor read/64, error -110
kernel: usb 1-2: device descriptor read/64, error -110

This is all running a fully up to date FC3.

The strange thing is if I boot a machine of a Knoppix CD (2.4 kernel) it 
all works fine and I can mount the disk OK.

Does anyone have any suggestions for how to troubleshoot this?

Cheers

Simon