Dead pretty much = Not port forwardedAnd I'm pretty sure if you go into the filters and choose none (or maybe one, try Passworded) it does that.
Because when you do that, the max ping is 999. Dead is counted as above 999.
Really? I've seen 1024 ping and 3027 ping once.
When you go into the filter menus the highest option for ping is 999, which will remove dead servers and those ones. Otherwise it just shows everything.