I have an Asus DSL N13 300mbps wireless router and use a TP Link 150mbps USB Wifi adapter and get an excellent signal btw. There are also a couple more devices connected to the network. Using Firefox I have had this problem for ages because every time I watch Youtube videos or when loading a page with pictures it will pause loading the page or if watching BBC Iplayer affect that and sometimes I have to load the whole page to start playback again though not 100% of the time. I can still access the routers admin panel on 192.168.1.1 when the connection seems to drop which is strange so this tells me it has a problem loading certain things like media and the actual wifi connection, it also drops for other users on the internet at the same time. I have the latest Asus firmware on the router and the ADSL stats are not reset while it drops, so it looks to me. Is there anything I can do, I know other Asus owners have similar disconnection issues from reading their own forum.
Also should have said that the wifi adapter in Windows does not show it being disconnected, I just have to wait a few seconds before I can start browsing again.