Ubuntu 13.04 wireless problems on Lenovo G580

[Heinzelmannchen]

I can't get my wireless card (BCM 4313) to connect to the internet. I tried multiple guides but to no avail, i tried installing B43 and had a connection for a few seconds although it was so weak i couldn't even use it. I'm sorry to be asking this i'm sure it gets irritating seeing all the noobie questions when there are guides but i've followed a few and can't get it working. In the system settings it says BRCM propiety driver is not working. Luckily i have an ethernet connection so i'm hoping this will be an easy fix. All help is appreciated.

lspci | grep Network

02:00.0 Network controller: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller (rev 01)

iwconfig

eth0 no wireless extensions.

lo no wireless extensions.

wlan0 IEEE 802.11bgn ESSID:off/any
Mode:Managed Access Point: Not-Associated Tx-Power=19 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Power Management:off

[Heinzelmannchen]

The following commands worked

sudo apt-get update

sudo apt-get -y install broadcom-sta-common

sudo reboot

But the connection is only 3 bars when it should be stronger any ideas on how to make the connection stronger? I have full bars on ubuntu 12.1