WiFi freezes and stops working

[Pphax]

Hi, i'm kinda new at linux and i am getting some troubles with WiFi. I got a Lenovo G550 with a BCM4312, at first i found some troubles making it work but i managed to find a proper driver and it is working "fine"
Every 5 minutes or so my WiFi freezes and internet stops working. I don't get disconnected from the network, but until i don't reconnect to it, internet will not work.

Rare thing is, i realised that this happens ONLY when my notebook is plugged in. When it's working on battery, this does not happen. If i use it on battery it works for 30-40 mins (or more) and 3 minutes after i plug it in, it just stops working.

I'm using Ubuntu 10.10, if there is any information i could give, just tell me. Thanks!

Oh, I also have a Windows partition and this does not happen there, either plugged in or on battery.

Thanks!

[mikewhatever]

What driver do you use, and where did you get it from? Is it a Windows driver, or have you used the Additional Driver utility?

[Pphax]

http://www.broadcom.com/support/802.11/linux_sta.php

I'm using those drivers, here is a screenshot:

[Pphax]

Any ideas? this is really annoying : (