New, 3.1 Software corrected the Wi-Fi problem on my iPhone 3G
For a few weeks now I have not been able to even search for Wi-fi networks with my iPhone 3G. The AT&T store said there was nothing to do other than call Apple. Best Buy (I have their $15/mo iPhone warranty) said I would have to replace my iPhone by letting them keep it and they would ship me another one “in a few days.” Apple said that I DID need a replacement iPhone and could go through them directly if I wanted to.
After the 3.1 software upgrade through iTunes I now have my Wi-Fi back!
Here is a HUGE discussion and workthroughs many people participated in:
http://discussions.apple.com/thread.jspa?threadID=2044754&start=0&tstart=0
I will cross my fingers and hope the fix is permanent.