WiFi Problems After 4.2.1.Update?

No, I have had no loss of WiFi after the upgrade.

No problems here

I have the same problem. 3G

the wife and I are both having this issue. Except it goes in and out of wifi. Also, it says wifi is on, but it says 3g. both phones are 3G.

Same problem here connect to wifi but still has the 3g symbol

I have a 3G, upgraded 3 hours (of troubleshooting) ago.
WiFi authentication doesn't work (at least on the office network, still have to try at home).

If I check my Cisco WLC, I can see the phone connected to the network infrastructure, but not authenticated (tried probably 50 times, no typos still possible) - and it gets one of those dreadful 169.254.x.x addresses.

After the last reboot, it seems to have lost even the ability to see the SSIDs.

Any suggestions?

Thanks,
Alfonso

I have a similar problem with my 3G phone, WI-FI comes and goes, but has nothing to do with the new IOS Upgrade (4.2.1)the root of this problem is from before, I understand it is apple's software that causes this problem, I had 3.1.2 when started doing this, I thought that upgrading to 4.0 will fix it (when it came out) but no luck there, right now is working after I did a restore on Iphone, and is been working fine using 4.2.1, I do NOT Sync iphone with Itunes, I use Itunes to Backup my phone only, my apps update are done separately (Iphone/Itunes) don't sync anymore, this works for me.

After updating my 32GB AT&T iPhone 4 to iOS 4.2.1, the Wi-Fi no longer finds any networks. Immediately prior to this update, the phone found and connected to all networks without issue.

I've tried toggling the Wi-Fi power, resetting the phone, and doing a complete restore, none of which solved the problem. I'm led to believe that this is an issue with this recent software release, and not a hardware problem with my phone.

Please Apple, let us know if this is a known issue, and if so, is there anything we can do to fix it, or will there be a software update to rectify the problem?

Same problem here. 3G. During a day or two it became a minor problem. Later on, no access.

Ditto, but iPhone 4. Wi-fi worked perfectly w 4.0.1, but with 4.2.1 it frequently disconnects, and is unable to connect when attempting to re-connect. When it is completely unable to connect, it seems to work again after disabling my MobileMe Find My Phone account, but that's probably not related.

I have same problem and have tried resetting network connections, forget this connection and all other suggestions but still have no stability. I rang Apple this morning and they say they have had no recorded issues regarding the instability of the wireless with the latest software version

I have same problem with iphone 4 with ios 4.2.1 and i tried everything but nothing could fix my problem and i am afraid that it might be hardware problem in iphone 4 and i tried to do samething as this man in this video
http://m.youtube.com/index?desktop_uri=/&gl=US

and i figured that he was right and what happened with him happen with me too and u can try by yourselfs in your iphone devices...

Message was edited by: tad88

The Youtube link in the previous post is broken, but I found another video that describes my problem(s) accurately:
http://www.youtube.com/watch?v=cMcPxrtsUMs
I tried to disable "Location Services" and that seemed to improve the problem, at least temporarily. Then I disabled 802.11 b on my router and only allowed 802.11 g. That also seemed to improve things, but hard to tell without more testing and time.