This thread on Ubuntu forums describes fixes for issues surrounding the Broadcom BCM4328 card:
1) Uninstall and reinstall the STA driver (in System > Administration > Hardware Drivers)
2) Install the b43-fwcutter package via Synaptic or apt-get (using a wired connection)
3) Run the following two commands in a terminal:
sudo rmmod ssb sudo modprobe wl
You might also try the steps listed in my other post regarding Ubuntu Karmic and Broadcom Wireless BCM4312 rev 01, and BCM4318 [Airforce One 54g] in Ubuntu Natty.
Comments / feedback regarding this are welcome.
