I tried to DMZ my PS3 with .50 and .137 and it would ALWAYS fail the DNS setting. So I set it to .100 and it works fine. So being that my PS3 is DMZ'd I still get disconnected from the PSN. I just read someone's post about disabling the Media Server Connection and so I did that and opened all the ports you listed. BUT, being that my PS3 was DMZ'd, does opening those ports mean anything?
ALSO, what does disabling the Media server do?
One more for the night, is it common to get signed out of the network a couple times a night?