Apple Magic Trackpad Slow Respond

My new 2011 Mac Mini I just bought, when I am using Wi-Fi the Magic Trackpad start the not move smoothly on the screen. At first I think is because I do not have a lot RAM and Mini is "slow". But after I upgrade my RAM to 8GB, this still happen and also I find out the trackpad is not move smooth but my logitech MX mouse is working well, now is this a problem with my bluetooth and Wi-Fi card?