OK first let's try the reinstalling the firmware, and if that doesn't work try the wl drivers .. and if that doesn't work you'll have to describe the connection and issue a little better
Whilst connected to the interweb, run:
sudo apt-get install --reinstall build-essential linux-headers-generic dkms bcmwl-kernel-source linux-firmware firmware-b43-installer
Now check if your wireless works the way you expect it to
If not, try unloading the b43 driver, and loading the wl driver (your card is supposed to be supported by both drivers)
Be aware - swapping the drivers will NOT survive a reboot and will need to be re-applied, but if it works we can make it permanent.