Cannot see other devices on Places>Computer nor Desktop

[AOB]

After upgrading on 12 Jan 2011 on my PC with Ubuntu 10.04 (Lucid) I cannot see other devices ie another hard disk(winxp) as slave nor thumbdrive at the usb port. However my printer attached to usb is working fine when I print out. Help needed urgently as I need to backup some data file onto other media before I can either setup hard disk from backup or load Ubuntu 10.10 all over again. I can be reached at email: alexong2005@yahoo.com.sg

Thanks in advance.

Alex
Singapore