Sur le même ordinateur, mais sur le LXDE, j'ai le même comportement avec l'appareil photo. Donc le problème n'est pas relié directement à Openbox.
Version de PCmanFM 0.9.10. (sur LXDE en tout cas, je crois que c'est ça aussi sur Openbox Education)
Pour education, ce n'est pas live. Je l'installé en novembre dernier.
Sur mon autre ordinateur P4, (avec la distro que l'on ne peut nommer

) ça a toujours bien été et je viens de tester à l'instant avec mon remaster V3 de PCLinuxOS LXDE que j'avais installé dessus et ça va très bien (même version de PCmanFM). Aucun problème.
Donc, le problème a vraiment rapport avec l'ordinateur des enfants. Je n'ai pas d'autre distro sur cet ordinateur pour tester.
Alors j'enlève le Education du titre du post car pas lié nécessairement
Voici ce qu'il y a dans le var/log/syslog sur LXDE
klogd: usb 4-2: new high speed USB device using ehci_hcd and address 12
Jan 12 19:54:36 localhost klogd: usb 4-2: New USB device found, idVendor=04a9, idProduct=3126
Jan 12 19:54:36 localhost klogd: usb 4-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
Jan 12 19:54:36 localhost klogd: usb 4-2: Product: Canon Digital Camera
Jan 12 19:54:36 localhost klogd: usb 4-2: Manufacturer: Canon Inc.
Jan 12 19:54:36 localhost klogd: usb 4-2: USB disconnect, address 12
Jan 12 19:54:36 localhost klogd: usb 4-2: new high speed USB device using ehci_hcd and address 13
Jan 12 19:54:37 localhost klogd: usb 4-2: New USB device found, idVendor=04a9, idProduct=3126
Jan 12 19:54:37 localhost klogd: usb 4-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
Jan 12 19:54:37 localhost klogd: usb 4-2: Product: Canon Digital Camera
Jan 12 19:54:37 localhost klogd: usb 4-2: Manufacturer: Canon Inc.
Jan 12 19:54:37 localhost klogd: usb 4-2: USB disconnect, address 13
Jan 12 19:54:37 localhost klogd: usb 4-2: new high speed USB device using ehci_hcd and address 14
Jan 12 19:54:37 localhost klogd: usb 4-2: New USB device found, idVendor=04a9, idProduct=3126
Jan 12 19:54:37 localhost klogd: usb 4-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
Jan 12 19:54:37 localhost klogd: usb 4-2: Product: Canon Digital Camera
Jan 12 19:54:37 localhost klogd: usb 4-2: Manufacturer: Canon Inc.
Jan 12 19:54:38 localhost klogd: usb 4-2: USB disconnect, address 14
Jan 12 20:01:01 localhost CROND[3334]: (root) CMD (nice -n 19 run-parts --report /etc/cron.hourly)
Jan 12 20:01:01 localhost anacron[3340]: Anacron started on 2012-01-12
Jan 12 20:01:01 localhost anacron[3340]: Will run job `cron.daily' in 12 min.
Jan 12 20:01:01 localhost anacron[3340]: Jobs will be executed sequentially
Jan 12 20:08:46 localhost klogd: usb 2-2: USB disconnect, address 3
Jan 12 20:08:50 localhost klogd: usb 1-1: USB disconnect, address 3
Jan 12 20:11:35 localhost klogd: usb 4-2: new high speed USB device using ehci_hcd and address 15
Jan 12 20:11:36 localhost klogd: usb 4-2: New USB device found, idVendor=04a9, idProduct=3126
Jan 12 20:11:36 localhost klogd: usb 4-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
Jan 12 20:11:36 localhost klogd: usb 4-2: Product: Canon Digital Camera
Jan 12 20:11:36 localhost klogd: usb 4-2: Manufacturer: Canon Inc.
Jan 12 20:12:56 localhost klogd: usb 4-2: USB disconnect, address 15
Jan 12 20:12:56 localhost klogd: usb 4-2: new high speed USB device using ehci_hcd and address 16
Jan 12 20:12:56 localhost klogd: usb 4-2: New USB device found, idVendor=04a9, idProduct=3126
Jan 12 20:12:56 localhost klogd: usb 4-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
Jan 12 20:12:56 localhost klogd: usb 4-2: Product: Canon Digital Camera
Jan 12 20:12:56 localhost klogd: usb 4-2: Manufacturer: Canon Inc.
Jan 12 20:13:01 localhost anacron[3340]: Job `cron.daily' started
Jan 12 20:13:07 localhost klogd: ip_tables: (C) 2000-2006 Netfilter Core Team
Jan 12 20:13:12 localhost msec: Security Warning: these home directory should not be owned by someone else or writable :
Jan 12 20:13:12 localhost msec: user=uuidd(493) : home directory is group writable.
Jan 12 20:13:12 localhost msec: These are the ports listening on your machine :
Jan 12 20:13:12 localhost msec: Active Internet connections (only servers)
Jan 12 20:13:12 localhost msec: Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
Jan 12 20:13:12 localhost msec: tcp 0 0 *:smux *:* LISTEN 1817/snmpd
Jan 12 20:13:12 localhost msec: tcp 0 0 *:ipp *:* LISTEN 1791/cupsd
Jan 12 20:13:12 localhost msec: tcp 0 0 *:ipp *:* LISTEN 1791/cupsd
Jan 12 20:13:12 localhost msec: udp 0 0 *:snmp *:* 1817/snmpd
Jan 12 20:13:12 localhost msec: udp 0 0 *:5353 *:* 1778/avahi-daemon:
Jan 12 20:13:12 localhost msec: udp 0 0 *:20754 *:* 1669/dhclient
Jan 12 20:13:12 localhost msec: udp 0 0 *:56682 *:* 1778/avahi-daemon:
Jan 12 20:13:12 localhost msec: udp 0 0 *:bootpc *:* 1669/dhclient
Jan 12 20:13:12 localhost msec: udp 0 0 *:ipp *:* 1791/cupsd
Jan 12 20:13:12 localhost msec: udp 0 0 *:37950 *:* 1669/dhclient
Jan 12 20:13:13 localhost msec: Security Warning: change in network listening ports found :
Jan 12 20:13:13 localhost msec: - Added network listening ports : tcp 0 0 *:smux *:* LISTEN 1817/snmpd
Jan 12 20:13:13 localhost msec: - Added network listening ports : tcp 0 0 *:ipp *:* LISTEN 1791/cupsd
Jan 12 20:13:13 localhost msec: - Added network listening ports : tcp 0 0 *:ipp *:* LISTEN 1791/cupsd
Jan 12 20:13:13 localhost msec: - Added network listening ports : udp 0 0 *:snmp *:* 1817/snmpd
Jan 12 20:13:13 localhost msec: - Added network listening ports : udp 0 0 *:5353 *:* 1778/avahi-daemon:
Jan 12 20:13:13 localhost msec: - Added network listening ports : udp 0 0 *:20754 *:* 1669/dhclient
Jan 12 20:13:13 localhost msec: - Added network listening ports : udp 0 0 *:56682 *:* 1778/avahi-daemon:
Jan 12 20:13:13 localhost msec: - Added network listening ports : udp 0 0 *:bootpc *:* 1669/dhclient
Jan 12 20:13:13 localhost msec: - Added network listening ports : udp 0 0 *:ipp *:* 1791/cupsd
Jan 12 20:13:13 localhost msec: - Added network listening ports : udp 0 0 *:37950 *:* 1669/dhclient
Jan 12 20:13:13 localhost msec: - Removed network listening ports : tcp 0 0 *:smux *:* LISTEN 1811/snmpd
Jan 12 20:13:13 localhost msec: - Removed network listening ports : tcp 0 0 *:ipp *:* LISTEN 1787/cupsd
Jan 12 20:13:13 localhost msec: - Removed network listening ports : tcp 0 0 *:ipp *:* LISTEN 1787/cupsd
Jan 12 20:13:13 localhost msec: - Removed network listening ports : udp 0 0 *:snmp *:* 1811/snmpd
Jan 12 20:13:13 localhost msec: - Removed network listening ports : udp 0 0 *:50364 *:* 1774/avahi-daemon:
Jan 12 20:13:13 localhost msec: - Removed network listening ports : udp 0 0 *:5353 *:* 1774/avahi-daemon:
Jan 12 20:13:13 localhost msec: - Removed network listening ports : udp 0 0 *:16197 *:* 1665/dhclient
Jan 12 20:13:13 localhost msec: - Removed network listening ports : udp 0 0 *:bootpc *:* 1665/dhclient
Jan 12 20:13:13 localhost msec: - Removed network listening ports : udp 0 0 *:ipp *:* 1787/cupsd
Jan 12 20:13:13 localhost msec: - Removed network listening ports : udp 0 0 *:14852 *:* 1665/dhclient
Jan 12 20:13:15 localhost klogd: usb 4-2: USB disconnect, address 16
Jan 12 20:13:16 localhost klogd: usb 4-2: new high speed USB device using ehci_hcd and address 17
Jan 12 20:13:16 localhost klogd: usb 4-2: New USB device found, idVendor=04a9, idProduct=3126
Jan 12 20:13:16 localhost klogd: usb 4-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
Jan 12 20:13:16 localhost klogd: usb 4-2: Product: Canon Digital Camera
Jan 12 20:13:16 localhost klogd: usb 4-2: Manufacturer: Canon Inc.
Jan 12 20:13:20 localhost anacron[3340]: Job `cron.daily' terminated (mailing output)
Jan 12 20:13:20 localhost anacron[3340]: Can't find sendmail at /usr/sbin/sendmail, not mailing output
Jan 12 20:13:20 localhost anacron[3340]: Normal exit (1 job run)
Jan 12 20:13:43 localhost klogd: usb 2-1: USB disconnect, address 2
Jan 12 20:13:59 localhost klogd: usb 4-2: USB disconnect, address 17
Jan 12 20:13:59 localhost klogd: usb 4-2: new high speed USB device using ehci_hcd and address 18
Jan 12 20:13:59 localhost klogd: usb 4-2: New USB device found, idVendor=04a9, idProduct=3126
Jan 12 20:13:59 localhost klogd: usb 4-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
Jan 12 20:13:59 localhost klogd: usb 4-2: Product: Canon Digital Camera
Jan 12 20:13:59 localhost klogd: usb 4-2: Manufacturer: Canon Inc.
Jan 12 20:14:08 localhost klogd: usb 2-1: new low speed USB device using uhci_hcd and address 4
Jan 12 20:14:08 localhost klogd: usb 2-1: device descriptor read/64, error -71
Jan 12 20:14:08 localhost klogd: usb 2-1: device descriptor read/64, error -71
Jan 12 20:14:08 localhost klogd: usb 2-1: new low speed USB device using uhci_hcd and address 5
Jan 12 20:14:08 localhost klogd: usb 2-1: device descriptor read/64, error -71
Jan 12 20:14:08 localhost klogd: usb 2-1: device descriptor read/64, error -71
Jan 12 20:14:09 localhost klogd: usb 2-1: new low speed USB device using uhci_hcd and address 6
Jan 12 20:14:09 localhost klogd: usb 2-1: device not accepting address 6, error -71
Jan 12 20:14:09 localhost klogd: usb 2-1: new low speed USB device using uhci_hcd and address 7
Jan 12 20:14:10 localhost klogd: usb 2-1: device not accepting address 7, error -71
Jan 12 20:14:10 localhost klogd: hub 2-0:1.0: unable to enumerate USB device on port 1
Jan 12 20:14:10 localhost klogd: usb 4-2: USB disconnect, address 18
Jan 12 20:14:26 localhost klogd: usb 2-1: new low speed USB device using uhci_hcd and address 8
Jan 12 20:14:27 localhost klogd: usb 2-1: New USB device found, idVendor=04b3, idProduct=310b
Jan 12 20:14:27 localhost klogd: usb 2-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
Jan 12 20:14:27 localhost klogd: input: HID 04b3:310b as /devices/pci0000:00/0000:00:1d.1/usb2/2-1/2-1:1.0/input/input6
Jan 12 20:14:27 localhost klogd: generic-usb 0003:04B3:310B.0004: input,hidraw0: USB HID v1.00 Mouse [HID 04b3:310b] on usb-0000:00:1d.1-1/input0