After installing Ubuntu 11.04, my network has become disabled. Here is the output oflshw in terminal:

*-network DISABLED
       description: Wireless interface
       product: BCM4312 802.11b/g LP-PHY
       vendor: Broadcom Corporation
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: eth1
       version: 01
       serial: 00:21:00:58:65:5f
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=wl0 driverversion=5.100.82.38 latency=0 multicast=yes wireless=IEEE
802.11bg
       resources: irq:17 memory:d4600000-d4603fff