broadcom - Wireless disabled even though the direct connectin (thru modem) is working fine

Need help with my newly installed Ubuntu 12.04 system (dual booting along with Win 7), even thoguh I can use internet using the modem and directly plugging it, the wireless network is disabled and it says firmware missing.

I tried the following options:

1. Checking to see if the wireless is disabled using the hot keys (F2 or Ctrl+F2 , Fn+F2 keys), the wireless is working fine in Win 7 but not in Ubuntu.




2. I am able directly plug the laptop with the modem and able connect to Internet using Ubuntu.




3. From the top right hand menu bar, te Wireless networks options say "device not ready (firmware missing) and the Enable Wireless checkbox is checked.




4. tried the command rfkill list , it shows all are NOT blocked.

   
   
   
   

   0: phy0: Wireless LAN
   soft blocked:no
   Hard blocked: no

   
   
   

   1: dell-wifi: Wireless LAN
   soft blocked:no
   Hard blocked: no

   
   
   

   2: dell-bluetooth: BlueTooth
   soft blocked:no
   
   Hard blocked: no

   
   
   

   3: hci0 Bluetooth
   soft blocked:no
   Hard blocked: no




5. ifconfig command shows eth0 and lo (lcoalhost) up and running but the wlan0 option is not available to show unless I type ifconfig -a, when it shows wlan0 but its down.




6. The command lspci -vvnn | grep 14e4 shows

   
   
   

   04:00.0 network Controller [0280]: Broadcom Corp BCM4312 802.11b/g LP-PHY [14e4:4315] {rev 01)
   08:00.0 Ethernet Controller [0200]: Broadcom Corp Netlink BCM5784M Gigabit Ethernet PCIe [1434:1698] {rev 10)





7. The file /var/lib/NetworkManager/NetworkManager.state shows all options are true (networking enabled, wireless enabled, wwlanenabled and wimaxenabled all options are set to true).

8) 'additional drivers' in your Dash and/or Preferences do not bring up anything at all.

9) output for lshw -C network shows

*-network DISABLED
description : Wireless interface
physical id: 4

logical name: wlan0
serial: 78:e4_00"43:b6:ab
capabilities: ethernet physical wireless
Configuration: broadcast=yes driver=b43 driverversion=3.2.0.29-generic-pae firmware=N/A link=no multicast= yes wireless=IEEE 802.11bg