internet running sluggish
 

Hey, i have a dsl connection, shared with 4 other computers via a router and two switches. I have two linux machines and then 3 windows machines. I notice that the internet takes forever to load up a webpage, but I'm getting super fast download speeds with files e.g. 150kbp/s - 500 kbp/s. I just installed new firmware on my router, could this be the problem? i have the D-link DI-604.