A short time after accessing the internet, the browser/download times out. Before the timeout, the internet works OK briefly; afterwards, the wireless is still connected with a strong signal, but every internet access results in a timeout. When I leave the PC for a while, the internet is back just to timeout again as soon as I start using it. The same happens when I reconnect to the router. Also, when I surf the internet, it takes a couple of minutes until the timeout, but when I download something, it times out in a matter of seconds. The wireless adapter works just fine in Windows and internet via ethernet cable works just fine in Ubuntu.

Does anyone have the same problem or knows a solution.

I use Ubuntu 12.10 x64. The problem occurs since I installed ubuntu (which was a few days ago).

Here some stuff that might be usefull:

serus@serus-Ubuntu-PC:~$ lsusb
Bus 002 Device 002: ID 0cf3:1002 Atheros Communications, Inc. TP-Link TL-WN821N v2 802.11n [Atheros AR9170]

serus@serus-Ubuntu-PC:~$ lsmod
Module                  Size  Used by
carl9170               82083  0

serus@serus-Ubuntu-PC:~$ modinfo carl9170
filename:       /lib/modules/3.5.0-21-       generic/kernel/drivers/net/wireless/ath/carl9170/carl9170.ko
alias:          arusb_lnx
alias:          ar9170usb
firmware:       carl9170-1.fw
description:    Atheros AR9170 802.11n USB wireless

serus@serus-Ubuntu-PC:~$ iwconfig
wlan0     IEEE 802.11bgn  ESSID:"virginmedia0137463"  
          Mode:Managed  Frequency:2.462 GHz  Access Point: A0:21:B7:F8:29:B6   
          Bit Rate=240 Mb/s   Tx-Power=20 dBm   
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=66/70  Signal level=-44 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:1399  Invalid misc:18   Missed beacon:0

serus@serus-Ubuntu-PC:~$ sudo lshw -C network
*-network
   description: Wireless interface
   physical id: 1
   bus info: usb@2:2
   logical name: wlan0
   serial: 00:27:19:bb:00:19
   capabilities: ethernet physical wireless
   configuration: broadcast=yes driver=carl9170 driverversion=3.5.0-21-generic firmware=1.9.4 ip=192.168.0.6 link=yes multicast=yes wireless=IEEE 802.11bgn