you can download the non-free driver from the broadcom site here :
http://www.broadcom.com/support/802.11/linux_sta.php
download the driver for your appropriate architecture ( 32bit or 64
bit) and compile it.
I confirmed that the wireless card for which the driver I installed is
the same as the one on your laptop which you are trying.
Ask me if there are any further problems .
Satish