WiFi Problems After 4.2.1.Update?

Here is the video link again..

http://www.youtube.com/watch?v=b4nmCOg0s4c

I have a very strange problem. I have a 3GS with 4.2.1. At home, my phone connects to my wireless network but always defaults back to 3G. When I turn off Cellular Data to force it to use the WiFi, it tells me I don't have any internet connection, even when I know the network is working. The strange thing is that my wife has the exact same phone and software version and the WiFi on the home network is just fine! It's driving me nuts. When I compare the two phone settings on the network information page, the only difference is that, on the DHCP page, the working phone has active #s for IP address, Subnet Mask, Router and DNS. My phone doesn't have the last two. No idea if this is meaningful. I've tried everything: renewing lease, forgetting the network and joining again, and doing a hard reset. Nothing! Anyone have any ideas as to what's going on here and how to fix?

This is really unaccettable Apple in that case really su **, it is unaccettable that I make an upgrade, AN OFFICIAL UPGRADE, of my iphone 3g and i discover that I canno use anymore my WiFi because of some problems between the phone and the firmware...are we kidding? Are you cheating on us? I paid this phone, LOT of money, and now I want it functional at 100% even if is not covered by the warranty, ecc...how can I send an official letter to the customer care?

I am really angry because before upgrading my phone was working very well, without any problems and with the WIFI perfectly functional!

I cannot accept it, really.

Has anyone followed this article?
iOS: Recommended settings for Wi-Fi routers and access points
http://support.apple.com/kb/HT4199

"Before configuring or adjusting specific settings, perform the following steps:

Ensure that your Wi–Fi router's firmware is up to date.
If you are using a Wi–Fi base station, refer to this article for information on how to update it.
Verify that all Wi–Fi devices you intend to use support the settings recommended in this article.
If possible, back up your current Wi–Fi router's settings.
If necessary, refer to the product documentation or manufacturer's website.
Forget or remove the Wi-Fi settings for your network from any devices that connect to your Wi-Fi router. (This will prevent the devices from attempting to connect to your network with the old configuration.) You will need to reconnect these devices to your network once you've finished applying the new settings.
Configure all Wi–Fi base stations on the same network with the same settings. Not doing so will cause connectivity and reliability issues. On dual-band Wi–Fi base stations, configure both bands to have the same settings unless otherwise noted below......"

Yes, I have tried the recommended settings, and many others. Nothing seems to help. Looks like I will be downgrading to 4.0.1 which worked flawlessly.

Me too.
Detects no wifi network after software upgrade to 4.2.1. and today, the wifi setting is disabled. Can't click on Wifi in settings.
iphone 3G

I do have the same problem after upgrade to 4.2.1

Model: ipod 3G MC008ZP

Can't have WiFi even I downgraded the firmware back to 4.1. The apple support centre said it's a hardware problem.

So frustrated!!!!!!!!!!

Fortunately, my iPhone 4 Wifi works OK at work, using WEP, so I changed from WPA2 Personal at home to WEP, and now it's usable, but not great. It drops connection every now and then, but not as hopelessly often as before. My Apple TV 2 also worked a little better, for a while with WEP, but dropped connection eventually, so I had to switch to cable.. Apple should have added an Ethernet port on our iPhones, as they can't seem to manage to get Wifi to work reliably.

My iPhone 4 cannot connect to the internet at all after the 4.2.1 update, not through WiFi and not through 3G. I already talked to an adviser about it and I might need a replacement. I only had my phone for a week 😟 I'm very disappointed about Apple.

Mine stays conected for 2-3mins then will drop wifi. It still says it is connected but it wont load anything. I can turn it off and back on real fast and it works. it *****.

Hi, same problem after upgrading to OS 4.2.1. Seems to be a hardware incompatability with newer OS versions. Following the Apple policy this requiers the iphone to be repaired after warranty is over for over 200 EUR !
This is totally unacceptable to pay for software which is not working on the bought hardware - absolutely not !

This is definitely a 4.2.1 problem as my iPad started to experience the exact same connectivity issue: the iPad/iPhone indicates it's registered on the network, but it then does not have internet access. The good news is that I managed to fix the problem. The key was doing a reset of both my router and hard reset of the devise as well. Now, I had done a quick power on/off of my router before and it didn't seem to work. However, when I turned it off for over an hour and combined that with a hard reset of the iPad/iPhone, it seemed to fix the problem.

I have the same problem with my iphone 3G running OS 4.2.1. Could not scan for wireless network. I tried all the reset network settings (which resulted in Graying out of Wi-fi and "No Wi-fi" in settings). Then I followed the instructions to hard and soft boot the phone using the home key and the power button, that didn't work either. Next I resorted to the restore of the phone, that didn't work either. I turned on the Airplane settings, powered off the phone and turned it back on then turned off Airplane settings and the Wi-fi became available again (not greyed out). Unfortunately I'm back to the Could not scan for wireless network error message after trying to join my home wi-fi. It used to work prior to the OS 4.2.1 upgrade.

I'm right now a disappointed & angry iPhone 3GS owner.
I've always been very happy with iOS, the updates were most of the time
improving the phone in performance & features.

Anyway, since I updated to 4.2.1 & now 4.3 which i updated to yesterday, I still can't connect to WiFi at work (2 different Wifi networks) or at the Gym & my data plan ran out last month & i had to pay extra for any data usage on the phone, which is really annoying! I can't pick emails or check anything.

I can connect to my home Wireless so what is happening is not with all wireless routes but with some??

By the way, I have an iPhone 4 & iPhone 3GS at work as well & both are running 4.3 now & BOTH can't connect to the Wifi at work!

What I've tried so far on my phone:
1. Erase all data & settings.
2. Update to 4.3
3. Forget the wireless network.
4. Reset the phone.

PLEASE HELP this is very inconvenient.

Thanks

iPhone 3G, complete loss of WiFi on all networks. Asks me for my password (sometimes) and then tells me it is incorrect.

Also, now I keep getting a voicemail password screen (constantly). I don't have voicemail set up.

This is getting old fast.