I'm pretty sure its defective, but i'm waiting for the 3.1 update to come out to see whether its the phone or the firmware. But there are plenty of forums talking about the slow wifi on 3gs. at first my 3gs had slow wifi issue, had it replaced by apple. The funny thing is my first 3gs compared to my 3g the screen was slightly dimmer when brightness was set to half. When i had the phone replaced the wifi was the same, slow and on top of that, my accelometer was screwed up, everytime you hold the phone playing a game you have to hold it lopsided, and on top of that the brightness is set to max, whether you put the brightness at max or in the middle, no difference. so i have to get it replaced again. Basicly I realy don't thinkg the wifi issue is caused by the router, or the firmware, because if the 3g is fine 3gs should be fine running the same firmware. Like most people have suggested, puting your router on B rather than G, it help a bit. But as an example, on a 3mbps dsl my 3g shows 2.5 mbps were as my 3gs shows .3 mbps- 1mbps. So yeah its the wifi chip if you ask me.