My 4500 has the latest firmware and im running xp on one pc and windows 7 on another. Both are wireless, however when i run speed test on my laptop with xp i should get anywhere from .85-.95 mb/s upload speed. I get up to around the average of .90 mb/s then half way through testing upload speed on speedtest.net my upload speed drops to around .30 mb/s. Its not a gradual drop its instant. Any ideas why? I have ATT Uverse Home Gateway with a ethernet cord going to my dgl-4500 in my room about 100 feet away. My speeds on my other computer that is connected wirelessly also stays in the correct range. Any ideas? My dgl-4500 is in DMZ Plus mode on my home gateway. Also my download speeds do not drop when my upload does.