I am going to try and explain this as good as possible. My iphone disconnects from my home wifi and every other wifi I ever tried and just reverts to 3g, It works sometimes for maybe a download or two then reverts back. This problem only occured for maybe the last month prior to that i could connect to any wifi and it would work all day. I tried everything to fix it Restored Iphone Upgraded Iphone to 3.0 Upgraded to 3.1 Then Downgraded to 3.0 to be sure Also in between each restore and upgrade Reseted all network settings numerous times. Reseted home router numerous times and changed settings. So i went as far as buying new Wifi card got it today replaced it and same thing happens works for a bit then reverts back. My iphone is about 1 year old maybe time for new battery??? If anyone has ever ran across this problem please let me know how it went for you and what you have done?