wifi problem in iOS4

I'm having the exact same problem.

I have a 3G running 4.0 and I am running into the same problem. When I restart my phone the Wifi symbol will come back momentarily then turn off again. My phone says I'm connected but I'm not getting anything. I pressed "Renew Lease" and nothing happened. I know its a software issue because my Wifi source is certainly reliable and I have never encountered any issues with it, not to mention my Mac mini still runs off the same Wifi signal. I hope there is a quick fix for this and someone figures it out soon!!!

 

I'm having the same issue with my 3GS. Has anyone found a way around this?

 

Same trouble - very disappointing

I have a 3G and upgraded to v4 os, and not only do I now have trouble with getting my home wifi signal (which my macbook picks up just fine), I also have more trouble with my 3G connection - especially for outgoing calls. Also, has anyone using the 3G phone noticed a significant slowdown in speed after the software upgrade??? I SO wish I hadn't downloaded the new software - if it ain't broke, don't fix it!! Has anyone heard whether Apple acknowledges these issues, and if so, plans to fix them?

 

Yes—almost everybody with a 3G has . There's been quite a few articles about it. Doing a cold boot will help speed it back up (did for me and my wife's). Hold down the home and sleep buttons until it restarts a couple of times and then turns off completely (screen goes black). Then turn it back on. It'll take a few minutes to boot up but should be speedier.

For those with network issues, are you by chance connecting to a dual-band router?

 

Anyone figure out a way around this yet? I'm still having the same issue. I have a 3gs running iOS4. When I try to connect to the wireless AP at work all the ip address's in the settings page look like they're right, and shows me connected. But the status bar doesn't show me as connected to any wireless signal. I used to get a pop up screen a few seconds after i've connected and that is usually the log in screen for the wireless connection here at work. But now I don't even see the wireless signal in the status bar or the pop up log in screen at all.

 

exactly the same problem here... I wish I'd read about all these problems before upgrading to 4.0. The interesting thing is that I CAN connect to my home wifi still, but NOT any of the work/cafe/public airport wifi.. (this I assume rules out the theory I see on some forum, that it's hardware problem?)