ubuntu@ubuntu:~$ lsmod | grep usb
usblp                  15104  0 
usbhid                 29536  0 
hid                    28928  1 usbhid
usbcore               137864  5 usblp,usbhid,ehci_hcd,ohci_hcd
ubuntu@ubuntu:~$ # unplugging
ubuntu@ubuntu:~$ tail -f /var/log/messages 
Aug 19 20:44:11 ubuntu kernel: [  894.688000] usb 1-3: new full speed USB device using ohci_hcd and address 23
Aug 19 20:44:11 ubuntu kernel: [  894.900000] usb 1-3: configuration #1 chosen from 1 choice
Aug 19 20:44:11 ubuntu kernel: [  894.912000] /build/buildd/linux-source-2.6.22-2.6.22/drivers/usb/class/usblp.c: usblp0: USB Bidirectional printer dev 23 if 0 alt 0 proto 2 vid 0x04E8 pid 0x326C
Aug 19 20:44:40 ubuntu kernel: [  924.556000] usb 1-3: USB disconnect, address 23
Aug 19 20:44:40 ubuntu kernel: [  924.560000] /build/buildd/linux-source-2.6.22-2.6.22/drivers/usb/class/usblp.c: usblp0: removed
Aug 19 20:44:41 ubuntu kernel: [  924.736000] usb 1-3: new full speed USB device using ohci_hcd and address 24
Aug 19 20:44:41 ubuntu kernel: [  924.952000] usb 1-3: configuration #1 chosen from 1 choice
Aug 19 20:44:41 ubuntu kernel: [  924.960000] /build/buildd/linux-source-2.6.22-2.6.22/drivers/usb/class/usblp.c: usblp0: USB Bidirectional printer dev 24 if 0 alt 0 proto 2 vid 0x04E8 pid 0x326C
Aug 19 20:44:44 ubuntu kernel: [  928.532000] usb 1-3: USB disconnect, address 24
Aug 19 20:44:44 ubuntu kernel: [  928.536000] /build/buildd/linux-source-2.6.22-2.6.22/drivers/usb/class/usblp.c: usblp0: removed
Aug 19 20:45:39 ubuntu kernel: [  982.848000] usb 1-4: new full speed USB device using ohci_hcd and address 25
Aug 19 20:45:39 ubuntu kernel: [  983.060000] usb 1-4: configuration #1 chosen from 1 choice
Aug 19 20:45:39 ubuntu kernel: [  983.072000] /build/buildd/linux-source-2.6.22-2.6.22/drivers/usb/class/usblp.c: usblp0: USB Bidirectional printer dev 25 if 0 alt 0 proto 2 vid 0x04E8 pid 0x326C
Aug 19 20:45:42 ubuntu kernel: [  986.420000] audit(1187556342.548:748): PERMITTING w access to /cow/var/spool/cups/d00002-001 (cupsd(7771) profile /usr/sbin/cupsd active /usr/sbin/cupsd)
Aug 19 20:45:42 ubuntu kernel: [  986.420000] audit(1187556342.548:749): PERMITTING w access to /cow/var/spool/cups/.wh.d00002-001 (cupsd(7771) profile /usr/sbin/cupsd active /usr/sbin/cupsd)
Aug 19 20:45:42 ubuntu kernel: [  986.420000] audit(1187556342.548:750): PERMITTING attribute (size,mtime,ctime,) change to /cow/var/spool/cups/c00002 (cupsd(7771) profile /usr/sbin/cupsd active /usr/sbin/cupsd)
Aug 19 20:45:42 ubuntu kernel: [  986.420000] audit(1187556342.548:751): PERMITTING attribute (mode,ctime,) change to /cow/var/spool/cups/c00002 (cupsd(7771) profile /usr/sbin/cupsd active /usr/sbin/cupsd)
Aug 19 20:45:42 ubuntu kernel: [  986.420000] audit(1187556342.548:752): PERMITTING attribute (uid,gid,ctime,) change to /cow/var/spool/cups/c00002 (cupsd(7771) profile /usr/sbin/cupsd active /usr/sbin/cupsd)

ubuntu@ubuntu:~$ # surprize: the printer printed
ubuntu@ubuntu:~$  lpinfo -v
network socket
network beh
direct hpfax
direct hp
network http
network ipp
network lpd
direct parallel:/dev/lp0
direct usb://Samsung/ML-2010
direct scsi
network smb
ubuntu@ubuntu:~$