I have 13.04 on a Dell Inspiron 1564 with Broadcom 4312 WiFi card. The wl drivers cause kernel panic on linux-3.8 so I succesfully installed the b43 driver a couple of months ago. Now I have changed ISP and got a new router, and the connection drop when downloading software from internet to a 2008r2 using Remmina Client, and apt-get install on virtual machines in virtualbox.

I have no idea why this suddenly became a problem.. My phone does not loose the connection, just Ubuntu.

Output from /var/log/syslog after lost connection

rfkill list(after disconnecting):

0: phy0: Wireless LAN
Soft blocked: yes
Hard blocked: yes

I can use NetworkManager to disable wireless and then enable wireless to connect again. rfkill ublock all/wifi/0 removes only Soft blocked.

lshw -C network

*-network
   description: Wireless interface
   physical id: 4
   logical name: wlan0
   serial: 78:e4:00:78:d2:05
   capabilities: ethernet physical wireless
   configuration: broadcast=yes driver=b43 driverversion=3.8.0-32-generic firmware=478.104 ip=10.0.0.3 link=yes multicast=yes wireless=IEEE

lspci

04:00.0 Network controller: Broadcom Corporation BCM4312 802.11b/g LP-PHY (rev 01)

After waking from suspend and when booting, it takes about 40 sec to get network connection. This has been a problem all along AND a different question, but I mention it anyway.. cus it's annoying!

Please take a look and hopefully someone spot a problem! Thanks!