I installed ubuntu-server 12.04 on my PC , and I use an usb wireless card to join the network. It works ok when I boot up my PC , but the wireless disconnects after a while. I pkill wpa_supplicant and reload the driver rtl8192cu , then it works a again. Then it disconnect again after about a random minutes. Here is the syslog: 22384 May 29 21:49:27 homecenter kernel: [ 6450.459313] wlan1: authenticated 22385 May 29 21:49:27 homecenter kernel: [ 6450.459535] wlan1: associate with f4:ec:38:45:62:74 (try 1) 22386 May 29 21:49:27 homecenter kernel: [ 6450.469080] wlan1: RX AssocResp from f4:ec:38:45:62:74 (capab=0 x431 status=0 aid=3) 22387 May 29 21:49:27 homecenter kernel: [ 6450.469085] wlan1: associated 22388 May 29 21:49:27 homecenter wpa_supplicant[2342]: Associated with f4:ec:38:45:62:74 22389 May 29 21:49:27 homecenter kernel: [ 6450.481933] ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready 22390 May 29 21:49:27 homecenter wpa_supplicant[2342]: WPA: Key negotiation completed with f4:ec:38:45:62:7 4 [PTK=CCMP GTK=CCMP] 22391 May 29 21:49:27 homecenter wpa_supplicant[2342]: CTRL-EVENT-CONNECTED - Connection to f4:ec:38:45:62: 74 completed (auth) [id=0 id_str=] 22392 May 29 21:49:38 homecenter kernel: [ 6461.472014] wlan1: no IPv6 routers present 22393 May 29 21:49:38 homecenter ntpdate[2263]: step time server 91.189.94.4 offset 0.012758 sec 22394 May 29 21:49:51 homecenter ntpdate[2404]: step time server 91.189.94.4 offset -0.001190 sec 22395 May 29 21:54:38 homecenter kernel: [ 6762.052030] wlan1: deauthenticated from f4:ec:38:45:62:74 (Reas on: 2) 22396 May 29 21:54:38 homecenter wpa_supplicant[2342]: CTRL-EVENT-DISCONNECTED bssid=f4:ec:38:45:62:74 reas on=2 22397 May 29 21:54:38 homecenter kernel: [ 6762.064744] cfg80211: All devices are disconnected, going to re store regulatory settings 22398 May 29 21:54:38 homecenter kernel: [ 6762.064752] cfg80211: Restoring regulatory settings 22399 May 29 21:54:38 homecenter kernel: [ 6762.064757] cfg80211: Calling CRDA to update world regulatory d omain 22400 May 29 21:54:38 homecenter kernel: [ 6762.069938] cfg80211: Ignoring regulatory request Set by core s ince the driver uses its own custom regulatory domain 22401 May 29 21:54:38 homecenter kernel: [ 6762.069943] cfg80211: World regulatory domain updated: 22402 May 29 21:54:38 homecenter kernel: [ 6762.069945] cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp) 22403 May 29 21:54:38 homecenter kernel: [ 6762.069949] cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KH z), (300 mBi, 2000 mBm) 22404 May 29 21:54:38 homecenter kernel: [ 6762.069952] cfg80211: (2457000 KHz - 2482000 KHz @ 20000 KH z), (300 mBi, 2000 mBm) 22405 May 29 21:54:38 homecenter kernel: [ 6762.069956] cfg80211: (2474000 KHz - 2494000 KHz @ 20000 KH z), (300 mBi, 2000 mBm) 22406 May 29 21:54:38 homecenter kernel: [ 6762.069959] cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KH z), (300 mBi, 2000 mBm) 22407 May 29 21:54:38 homecenter kernel: [ 6762.069962] cfg80211: (5735000 KHz - 5835000 KHz @ 40000 KH z), (300 mBi, 2000 mBm)