Abit in9 32x-max wi-fi network problem

Hello , it's been a month or so that i have connection problems and i can't figure out what's going on. Basically what happens is, when i am downloading or when i am on internet for no reason at all my connection with the switch stops. Since i have 2 computers i know that this isn't the switch's problem or a problem with the ethernet cable. Thing is that when the connection stops the ethernet is still flashing as if everything was working correctly. The only way to fix this is by restarting.Logging or anything else doesn't seem to work. I ve tried a memtest but i didn't find out any problems.
I am using windows vista 64 my motherboard is an Abit in9 32max wi-fi and i am seriously out of ideas.
I ve noticed that most of the times when the connection stops working is when i am downloading at full connection speed.
Any help would be appreciated .

Thanks