Ming Lei, I don't really understand what you mean. I just follow your instruction without adding something.
I attached screenshot from Synaptic which shown usb related package. Maybe it could help you analize. ** Attachment added: "USB related package" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1159358/+attachment/3669634/+files/Screenshot%20from%202013-05-08%2016%3A01%3A05.png -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1159358 Title: USB Printer & HDD external can't wake up after a moment of time To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1159358/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
