I just installed Ubuntu 12.10 on my DELL Latitude E6230, on first boot wifi worked properly but when I updated the software it stopped working. I can't figure out the problem...

The wireless network controller is a Broadcom Corporation BCM4313 802.11b/g/n Wireless Lan Controller (rev 01)

"lshw -class network" gives, for the above controller:

*-network UNCLAIMED description: Network controller product: BCM4313 802.11b/g/n Wireless LAN Controller vendor: Broadcom Corporation physical id: 0 bus info: pci@0000:02:00.0 version: 01 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list configuration: latency=0 resources: memory:f7d00000-f7d03fff

After reading the answer to another similar question, I edited the file NetworkManager.conf to make "managed=true", but that did not make any difference, it is as if the wireless adapter were not there. In the "Network" setting window, I only see "Wired" and "Network proxy". Wireless has just disappeared:

rfkill list all 0: hci0: Bluetooth Soft blocked: no Hard blocked: no

and that's it! Nothing about the wireless controller...

Any suggestions?