iPod's WiFi doesn't work...

So whenever I'm in my Dad's Office (right next door to router), where my computer is, my iPod actually has 3 bars of internet connection, but it won't work. When I'm upstairs in my room, with 1-2 bars and the crappiest interent connection in the entire house, the Wi-Fi works! By Wi-Fi not working, I mean Apps like Safari, World War, App Store, Facebook etc.

My friend said it was because my Dad's computer, coupled with mine, took to much bandwidth up, but that can't possibly be the reason. I highly doubt that this problem affects everyone. Any suggestion for why this happens and how to fix it?