I tried this
[ubuntu] Working wireless broadcom b43 hardy 8.04 - Ubuntu Forums
and it worked the first time.
Now there is something else because the lamp that indicates that the card is running is working.(it wasnt the first time). Now I just cant find any wireless network. I dont know how this happend. The computer was left on and suddenly when I came back there was this problem.

The b43 driver and Ubuntu's standby/hibernate don't play well together. Did you try restarting the machine?

If this still fails, press the 'Fn' and wireless keys on your machine (if it is a laptop). This has been a headache for me in the past, and I wanted to kick myself when I realized what the problem really was -- the card was not enabled.

The wirelesskeys? Witch one may that be? You mean the one the one whit the lamp?

Not to sound mean, but you tell me. You're the one looking at the keyboard.

Assuming this is a laptop, if you don't know which "function + $KEY" combination addresses your wireless card, I suggest you reference the owner's manual.