About 8 months back , I upgraded my ubuntu 9.04 into 9.10 , only to realise that wifi didnt work in it. For some reasons, I had to revert back to 9.04 . This May , I installed ubuntu 10.04 and realised tht the wifi bug hadnt been fix. Here’s the bugfix (Thank you, Ubuntu forums) :-
To install the broadcom driver, go to the link given below.
Dell broadcom driver
The broadcom_fix.zip file is automatically downloaded from the above link.
Extract the file -> double click dell_net.sh -> run in terminal
The drivers are installed . Wifi works !
It works well for my Studio . I guess it will work for all dell laptops/laptops with broadcom wifi driver.