Wireless Intermitent

Hello,



I have two Laptops Dell Latitude 620. When I connect to wireless one of the laptops works properly . The other works intermitent. Is like the wireless loose the sigal for a second and then start again. If I try to see a video always download just the half of the video and stop then if you try again tha video or any other video stop exactly at the same position. The driver used in this laptop is Dell Wireless 1390 Mini card.