I have a 2.2 Telus Desire. One day my WIFI stopped working. I ended up doing a hard reset only to find I had the same problem. I was sure the WIFI card died. I took it back to the seller and it would connect at his shop. I returned home and it still would not work at my house All my laptops and desktops function normally and I even reset my router. In the end I got it working by shutting down one of my laptops. The Desire was trying to share an IP address with the laptop and it wouldnt transfer any data. THat was a real drag. Its problems like that that make technology suck.
It's not just you. I have an HTC Desire and I run the Wi-fi at work and at home. No problems at home... but at work, I have to reset the wireless router every day in order for the wi-fi to work on my phone. We never had to do this before I started using the wi-fi on my phone at work.
I logged into my D-Link router yesterday when my Desire lost internet. I still had the same IP and I couldn't see where it was sharing an IP. I turned off one of my laptops and presto the Desire started working again. This is a strange problem.
Samsung Galaxy SII Skyrocket, iPhone 4, Bold 9900, Sony Ericsson Xperia Arc S
I've had the same issue with a few different Android devices, ranging from a Galaxy S Captivate, to my Nexus One, to a Dell Streak. None of them will connect unless I reset my router, and even then, it's still not worth the hassle. My iPhones have never given me any issues.