This sound like a problem I was having a wile back. The only thing I did was changing auto DNS to googles 8.8.8.8 DNS. That fixed everything for me.
I had to constantly click "New search" for several minutes to even find half of all the running servers in the list. And most of the time the server I was looking for wasn't showing at all. Might be worth a try.
edit: Oh and I only changed it in the Network connection on the computer and not in the router/modem.