Hi!

I send more information about this bug. I activated the wlan by hand from the knetworkmanager. The connection was estabilished, but in some second was disconnected.
Here is the var/log/syslog

Mar 23 10:24:29 emerald NetworkManager: <info> Updating allowed wireless network lists.
Mar 23 10:24:29 emerald NetworkManager: <info> SWITCH: no current connection, found better connection 'wlan0'.
Mar 23 10:24:29 emerald dhcdbd: message_handler: message handler not found under /com/redhat/dhcp/wlan0 for sub-path wlan
0.dbus.get.reason
Mar 23 10:24:29 emerald NetworkManager: <info> Will activate connection 'wlan0/Sarpeidon'.
Mar 23 10:24:29 emerald NetworkManager: <info> Device wlan0 activation scheduled...
Mar 23 10:24:29 emerald NetworkManager: <info> Activation (wlan0) started...
Mar 23 10:24:29 emerald NetworkManager: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) scheduled...
Mar 23 10:24:29 emerald NetworkManager: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) started...
Mar 23 10:24:29 emerald NetworkManager: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) scheduled...
Mar 23 10:24:29 emerald NetworkManager: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) complete.
Mar 23 10:24:29 emerald NetworkManager: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) starting...
Mar 23 10:24:29 emerald NetworkManager: <info> Activation (wlan0/wireless): access point 'Sarpeidon' is encrypted, but N
O valid key exists. New key needed.
Mar 23 10:24:29 emerald NetworkManager: <info> Activation (wlan0) New wireless user key requested for network 'Sarpeidon
'.
Mar 23 10:24:29 emerald NetworkManager: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) complete.
Mar 23 10:24:29 emerald NetworkManager: <WARN> nm_dbus_get_user_key_for_network_cb(): nm_dbus_get_user_key_for_network_c
b(): dbus returned an error. (org.freedesktop.NetworkManagerInfo.GetKeyError) org.freedesktop.NetworkManagerInfo.GetKey
Error
Mar 23 10:24:29 emerald NetworkManager: <info> Activation (wlan0) failure scheduled...
Mar 23 10:24:30 emerald NetworkManager: <info> Activation (wlan0) failed for access point (Sarpeidon)
Mar 23 10:24:30 emerald NetworkManager: <info> Activation (wlan0) failed.
Mar 23 10:24:30 emerald NetworkManager: <info> Deactivating device wlan0.
Mar 23 10:24:47 emerald NetworkManager: <debug> [1206264287.872099] nm_device_802_11_wireless_get_activation_ap(): Forcin
g AP 'Sarpeidon'
Mar 23 10:24:47 emerald NetworkManager: <info> User Switch: /org/freedesktop/NetworkManager/Devices/wlan0 / Sarpeidon
Mar 23 10:24:47 emerald NetworkManager: <info> Deactivating device wlan0.
Mar 23 10:24:47 emerald dhcdbd: message_handler: message handler not found under /com/redhat/dhcp/wlan0 for sub-path wlan
0.dbus.get.reason
Mar 23 10:24:47 emerald NetworkManager: <info> Device wlan0 activation scheduled...
Mar 23 10:24:47 emerald NetworkManager: <info> Activation (wlan0) started...
Mar 23 10:24:47 emerald NetworkManager: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) scheduled...
Mar 23 10:24:47 emerald NetworkManager: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) started...
Mar 23 10:24:47 emerald NetworkManager: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) scheduled...
Mar 23 10:24:47 emerald NetworkManager: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) complete.
Mar 23 10:24:47 emerald NetworkManager: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) starting...
Mar 23 10:24:47 emerald NetworkManager: <info> Activation (wlan0/wireless): access point 'Sarpeidon' is encrypted, and a
 key exists. No new key needed.
Mar 23 10:24:50 emerald NetworkManager: <info> supplicant_interface_init() - connect to global ctrl socket (0/10).
Mar 23 10:24:50 emerald NetworkManager: <info> supplicant_interface_init() - connect to global ctrl socket (1/10).
Mar 23 10:24:50 emerald NetworkManager: <info> SUP: sending command 'INTERFACE_ADD wlan0^I^Iwext^I/var/run/wpa_supplican
t5^I'
Mar 23 10:24:51 emerald kernel: [ 141.047801] NET: Registered protocol family 17
Mar 23 10:24:51 emerald NetworkManager: <info> SUP: response was 'OK'
Mar 23 10:24:51 emerald NetworkManager: <info> supplicant_init() - connect to device ctrl socket (1/10).
Mar 23 10:24:51 emerald NetworkManager: <info> SUP: sending command 'AP_SCAN 1'
Mar 23 10:24:51 emerald NetworkManager: <info> SUP: response was 'OK'
Mar 23 10:24:51 emerald NetworkManager: <info> SUP: sending command 'ADD_NETWORK'
Mar 23 10:24:51 emerald NetworkManager: <info> SUP: response was '0'
Mar 23 10:24:51 emerald NetworkManager: <info> SUP: sending command 'SET_NETWORK 0 ssid 536172706569646f6e'
Mar 23 10:24:51 emerald NetworkManager: <info> SUP: response was 'OK'
Mar 23 10:24:51 emerald NetworkManager: <info> SUP: sending command 'SET_NETWORK 0 proto WPA2'
Mar 23 10:24:51 emerald NetworkManager: <info> SUP: response was 'OK'
Mar 23 10:24:51 emerald NetworkManager: <info> SUP: sending command 'SET_NETWORK 0 key_mgmt WPA-PSK'
Mar 23 10:24:51 emerald NetworkManager: <info> SUP: response was 'OK'
Mar 23 10:24:51 emerald NetworkManager: <info> SUP: sending command 'SET_NETWORK 0 psk <key>'
Mar 23 10:24:51 emerald NetworkManager: <info> SUP: response was 'OK'
Mar 23 10:24:51 emerald NetworkManager: <info> SUP: sending command 'ENABLE_NETWORK 0'
Mar 23 10:24:51 emerald NetworkManager: <info> SUP: response was 'OK'
Mar 23 10:24:51 emerald NetworkManager: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) complete.
Mar 23 10:24:52 emerald NetworkManager: <info> Activation (wlan0/wireless) Stage 2 of 5 (Device Configure) successful.
Connected to access point 'Sarpeidon'.
Mar 23 10:24:52 emerald NetworkManager: <info> Activation (wlan0) Stage 3 of 5 (IP Configure Start) scheduled.
Mar 23 10:24:52 emerald NetworkManager: <info> Activation (wlan0) Stage 3 of 5 (IP Configure Start) started...
Mar 23 10:24:52 emerald kernel: [ 142.000472] wlan0: Initial auth_alg=0
Mar 23 10:24:52 emerald kernel: [ 142.000485] wlan0: authenticate with AP 00:18:f3:4d:c1:8d
Mar 23 10:24:52 emerald kernel: [ 142.002121] wlan0: RX authentication from 00:18:f3:4d:c1:8d (alg=0 transaction=2 statu
s=0)
Mar 23 10:24:52 emerald kernel: [ 142.002128] wlan0: authenticated
Mar 23 10:24:52 emerald kernel: [ 142.002134] wlan0: associate with AP 00:18:f3:4d:c1:8d
Mar 23 10:24:52 emerald kernel: [ 142.004614] wlan0: RX AssocResp from 00:18:f3:4d:c1:8d (capab=0x411 status=0 aid=1)
Mar 23 10:24:52 emerald kernel: [ 142.004622] wlan0: associated
Mar 23 10:24:53 emerald NetworkManager: <info> Activation (wlan0) Beginning DHCP transaction.
Mar 23 10:24:53 emerald NetworkManager: <info> Activation (wlan0) Stage 3 of 5 (IP Configure Start) complete.
Mar 23 10:24:53 emerald NetworkManager: <info> DHCP daemon state is now 12 (successfully started) for interface wlan0
Mar 23 10:24:53 emerald dhclient: wmaster0: unknown hardware address type 801
Mar 23 10:24:54 emerald NetworkManager: <info> DHCP daemon state is now 1 (starting) for interface wlan0
Mar 23 10:24:54 emerald dhclient: wmaster0: unknown hardware address type 801
Mar 23 10:24:54 emerald dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 5
Mar 23 10:24:54 emerald dhclient: DHCPOFFER from 192.168.1.1
Mar 23 10:24:54 emerald dhclient: DHCPREQUEST on wlan0 to 255.255.255.255 port 67
Mar 23 10:24:54 emerald dhclient: DHCPACK from 192.168.1.1
Mar 23 10:24:54 emerald avahi-daemon[5216]: Joining mDNS multicast group on interface wlan0.IPv4 with address 192.168.1.3
.
Mar 23 10:24:54 emerald avahi-daemon[5216]: New relevant interface wlan0.IPv4 for mDNS.
Mar 23 10:24:54 emerald avahi-daemon[5216]: Registering new address record for 192.168.1.3 on wlan0.IPv4.
Mar 23 10:24:55 emerald NetworkManager: <info> DHCP daemon state is now 2 (bound) for interface wlan0
Mar 23 10:24:55 emerald NetworkManager: <info> Activation (wlan0) Stage 4 of 5 (IP Configure Get) scheduled...
Mar 23 10:24:55 emerald NetworkManager: <info> Activation (wlan0) Stage 4 of 5 (IP Configure Get) started...
Mar 23 10:24:55 emerald dhcdbd: message_handler: message handler not found under /com/redhat/dhcp/wlan0 for sub-path wlan
0.dbus.get.host_name
Mar 23 10:24:55 emerald dhcdbd: message_handler: message handler not found under /com/redhat/dhcp/wlan0 for sub-path wlan
0.dbus.get.domain_name
Mar 23 10:24:55 emerald dhcdbd: message_handler: message handler not found under /com/redhat/dhcp/wlan0 for sub-path wlan
0.dbus.get.nis_domain
Mar 23 10:24:55 emerald dhcdbd: message_handler: message handler not found under /com/redhat/dhcp/wlan0 for sub-path wlan
0.dbus.get.nis_servers
Mar 23 10:24:55 emerald NetworkManager: <info> Retrieved the following IP4 configuration from the DHCP daemon:
Mar 23 10:24:55 emerald NetworkManager: <info> address 192.168.1.3
Mar 23 10:24:55 emerald NetworkManager: <info> netmask 255.255.255.0
Mar 23 10:24:55 emerald NetworkManager: <info> broadcast 192.168.1.255
Mar 23 10:24:55 emerald NetworkManager: <info> gateway 192.168.1.1
Mar 23 10:24:55 emerald NetworkManager: <info> nameserver 192.168.1.1
Mar 23 10:24:55 emerald NetworkManager: <info> Activation (wlan0) Stage 5 of 5 (IP Configure Commit) scheduled...
Mar 23 10:24:55 emerald NetworkManager: <info> Activation (wlan0) Stage 4 of 5 (IP Configure Get) complete.
Mar 23 10:24:55 emerald NetworkManager: <info> Activation (wlan0) Stage 5 of 5 (IP Configure Commit) started...
Mar 23 10:24:55 emerald avahi-daemon[5216]: Withdrawing address record for 192.168.1.3 on wlan0.
Mar 23 10:24:55 emerald avahi-daemon[5216]: Leaving mDNS multicast group on interface wlan0.IPv4 with address 192.168.1.3
.
Mar 23 10:24:55 emerald avahi-daemon[5216]: Interface wlan0.IPv4 no longer relevant for mDNS.
Mar 23 10:24:55 emerald avahi-daemon[5216]: Joining mDNS multicast group on interface wlan0.IPv4 with address 192.168.1.3
.
Mar 23 10:24:55 emerald avahi-daemon[5216]: New relevant interface wlan0.IPv4 for mDNS.
Mar 23 10:24:55 emerald avahi-daemon[5216]: Registering new address record for 192.168.1.3 on wlan0.IPv4.
Mar 23 10:24:55 emerald dhclient: bound to 192.168.1.3 -- renewal in 36605 seconds.
Mar 23 10:24:56 emerald NetworkManager: <info> Clearing nscd hosts cache.
Mar 23 10:24:56 emerald NetworkManager: <WARN> nm_spawn_process(): nm_spawn_process('/usr/sbin/nscd -i hosts'): could no
t spawn process. (Failed to execute child process "/usr/sbin/nscd" (No such file or directory))
Mar 23 10:24:56 emerald NetworkManager: <info> Activation (wlan0) successful, device activated.
Mar 23 10:24:56 emerald NetworkManager: <info> Activation (wlan0) Finish handler scheduled.
Mar 23 10:24:56 emerald NetworkManager: <info> Activation (wlan0) Stage 5 of 5 (IP Configure Commit) complete.
Mar 23 10:24:56 emerald ntpdate[6149]: adjust time server 91.189.94.4 offset -0.136224 sec
Mar 23 10:24:57 emerald NetworkManager: <info> SWITCH: terminating current connection 'wlan0' because it's no longer val
id.
Mar 23 10:24:57 emerald NetworkManager: <info> Deactivating device wlan0.
Mar 23 10:24:57 emerald dhclient: There is already a pid file /var/run/dhclient.wlan0.pid with pid 6089
Mar 23 10:24:57 emerald dhclient: killed old client process, removed PID file
Mar 23 10:24:57 emerald dhclient: wmaster0: unknown hardware address type 801
Mar 23 10:24:57 emerald dhclient: wmaster0: unknown hardware address type 801
Mar 23 10:24:57 emerald dhclient: DHCPRELEASE on wlan0 to 192.168.1.1 port 67
Mar 23 10:24:57 emerald avahi-daemon[5216]: Withdrawing address record for 192.168.1.3 on wlan0.
Mar 23 10:24:57 emerald avahi-daemon[5216]: Leaving mDNS multicast group on interface wlan0.IPv4 with address 192.168.1.3
.
Mar 23 10:24:57 emerald avahi-daemon[5216]: Interface wlan0.IPv4 no longer relevant for mDNS.
Mar 23 10:24:58 emerald NetworkManager: nm_device_is_802_3_ethernet: assertion `dev != NULL' failed
Mar 23 10:24:58 emerald NetworkManager: nm_device_is_802_11_wireless: assertion `dev != NULL' failed
Mar 23 10:24:58 emerald kernel: [ 148.085907] wlan0: deauthenticate(reason=3)

After the disconnection I could reconnect.

In some cases the disconnection happean in minutes or in hours. One time I could reconnect, other time I couldn't. If I reproduce these cases, I send more syslogs.