This may be present on the original HTC Desire, I'm not sure, but I'm running the insertcoin DHD rom. I have been getting poor performance out of my Wifi (I let my phone download the United Kingdom map from locations overnight and it was still going after 8 hours even though I have a 50mbit connection!) I decided to look around the Wifi options and I found something in the "Advanced" menu of the WiFi settings that says "Best Wi-Fi performance" and ticked it. My WiFi is now really fast again. Just wanted to share this in case anybody else is getting poor performance from their WiFi!