usb2 hard drive not being recognised anymore

[Thomas McLean]

Hi all,

First of all for informational purposes I am running Dapper.

I have a 500gb external usb2 hdd which I have been using for the past 
couple of days. Anyway, I rebooted my machine and when I try to mount 
the hdd it just says:
 'tam at spud:~$ sudo mount -t ext3 /dev/sda1 /mnt/big
mount: special device /dev/sda1 does not exist'

Well at that point I thought I should check to see if the modules are 
present and here is the output from that also:

tam at spud:~$ lsmod |grep usb
usb_storage            74176  0
scsi_mod              139496  4 sd_mod,usb_storage,sr_mod,sbp2
usbcore               129668  4 usb_storage,ehci_hcd,ohci_hcd

dmesg reports this whenever I put in the usb2 cable:
[4294852.023000] usb 4-4: USB disconnect, address 2
[4295590.979000] usb 4-4: new high speed USB device using ehci_hcd and 
address 3
[4295953.814000] Initializing USB Mass Storage driver...
[4295953.814000] usbcore: registered new driver usb-storage
[4295953.814000] USB Mass Storage support registered.
[4296229.694000] Driver 'sd' needs updating - please use bus_type methods
[4296247.023000] usb 4-4: USB disconnect, address 3
[4296249.229000] usb 4-4: new high speed USB device using ehci_hcd and 
address 4
[4296249.733000] usb 4-4: device not accepting address 4, error -71
[4296249.835000] usb 4-4: new high speed USB device using ehci_hcd and 
address 5


Now at the moment I really don't know what else I can do to get the hdd 
working and was hoping that some member of the list knows where I am 
going wrong or can give some handy tips so that I can resolve my problem.

Many thanks in advance.

Tam.