Duemilanove not recognised in Fedora 10

I recently purchased a Duemilanove but cannot get Fedora 10 to recognise the ftdi chip. I have installed the libftdi package and done modprobe ftdi-sio but still get
usb 1-1: device not accepting address 21, error -71
hub 1-0:1.0: unable to enumerate USB device on port 1.
Any ideas as to how I can get this working? I have read LOADS of guides on the net but to no avail.