Strange WiFi problem on iPhone 3G after 3.0 update

*UPDATED POST #2*

*IN AN EARLIER POST I REPORTED THE FOLLOWING:*

<<I followed the recommendations offered by 999aaa (THANKS A MILLION!!) and set my router to transmit out with "g only" (my Belkin router 3 has options: "n only", "g only", or "g nb") and so far problem is solved. I also did a reset of my iPhone Network Connections after I changed the router (as recommended by other users: Go to SETTINGS/GENERAL/RESET/RESET NETWORK SETTINGS - after this you'll need to reenter your router password when reconnecting) My iPhone is again reconnecting to my WiFi automatically, and speed was not affected.The question remains - why is this happening with the 3.0 upgrade? I had no problem with my router set to "g nb" and the 2.2.1 OS. Likely a bad 3.0 glitch...>>

*WELL, PROBLEM IS BACK...*
After what appeared to have been a 12+ hour period of WiFi connectivity back to normal, I'm back to square one, i.e., my WiFi connection hangs up if phone goes to sleep or if I play a game. Even when the WiFi icon is showing a good connection I'm not connecting - Safari freezes with the spinning icon going around and around. Any application requiring an internet connection (like AP News or NYTimes) will freeze as well. The only way to reconnect is to turn the iPhone's WiFi off and then turn it back on again.

A new observation (significance?) is that my WiFiTrak application will not initiate, showing an error message which says "COULD NOT PROPERLY INITIATE THE WIFI SCANNER"

Thanks to everyone who's written solutions, but...

None of these have worked for me. My router is old and thus is already in B & G mode. I took off the password protection so none of that could be an issue and it hasn't changed. I've tried joining wifi hookups at different places. And of course I've resetted, rebooted, reinstalled, turned features off, turned them back on, a thousand different times with no change.

EVERY SINGLE TIME I TRY TO JOIN A WIFI NETWORK, MY IPHONE TELLS ME IT IS UNABLE TO DO SO.

Just ridiculous. I've actually just had wifi off for the last few days because I get very frustrated if it's trying when I'm loading up web info.

Looks like I'm off to the genius bar to get a new phone.

I'm still suffering this. I've tried:
a) resetting network settings
b) wipe & restore
c) reconfiguring router
and none of it works. I've even tried all the random anecdotal things like 'boot up without a SIM card in' with no luck. The only time the wifi works fine is at very low battery levels (<25%).

Now here's my big problem. I live nowhere near an Apple Store. My nearest one is hundreds of miles away. How can I get Apple to replace the thing for me? Or at the very least, does anyone know when we can expect a patch for this?

i'm having a similar problem since 3.0. iphone sees my wireless network just fine but network resets, lease renewals, reboots, router resets - nothing will force my iphone from 3g mode into actually using the wireless.

btw- the bluetooth, which i never really use, won't connect to my laptop either.

I had a problem with my wifi connection dropping every time I put the phone into standby. What I realized was that after upgrading my phone to the 3GS and doing a full restore, the iPhone had restored the wrong wifi password. So even though I was able to connect when I first started up the iPhone by entering the password in manually, when I went into standby and then came back out of standby, the iPhone went back to some stored / cached wrong password and would not connect. To resolve this, I manually connected to the wifi network and then right away went in and told it "forget this network." Then the next time I manually added the password, it stored it correctly and coming out of standby kept my wifi connection from that point on.

So it appears that the restore saved the wrong password somehow, which is really strange. The strangest part is that I have not changed that wifi password recently, so I have no idea what wrong password it was using.

I have the same problem. No wifi- won't find my network (macbook does). I successfully paired the phone with laptop (bluetooth) but phone will not connect to laptop. In my car the bluetooth on the iphone says it's not connected, but the hands free in the car shows the connection. It was fine before 3.0 update.

I am having wifi connection problems on a 3G with 3.0 similar to many others here. I can get a connection if I do a hard reset of the phone and it will stay connected for a period of time. However, if the iphone is shut off (or it "sleeps") for any period of time there is no wifi connection upon waking up/turning on. Although the icon may be present on the upper left corner of the screen, no internet connection exists. Likewise, if I web browse for a period of time or look at a YouTube video, the connection fails at a certain point. I've tried every suggestion on this post in any and all combination's (the exception being that I have not tested wifi after a restore without the backup installed -- that is my next and last step). I did not have this problem prior to 3.0, but my situation is complicated by the fact that my phone was concurrently replaced for a cracked casing, so it is possible that I have a defective reconditioned unit and this is not a software problem. I will try the factory restore with no backup installed and then it is a trip to the Genius bar although I am skeptical about what they can do to fix this.

After upgrading my iPhone 3G to OS 3.0 I am also experiencing Wifi problems: the phone seems to refuse automatic connection to my home wifi network (and switch to my EDGE account)altough my home network is detected in the settings>general>wi-fi menu. After manually connecting to the wifi network, connection gets lost after some time, and switches back to EDGE... I experienced no problems like this while running OS 2.x...

Hopefully some guy at Apple reads this topic and takes note of it or provides a solution...

About WifiTrak: The App currently doesn't work with OS 3.0, as the developer states, so the error message is quite justified and nothing to worry about.

For me, the iPhone still requires an insanely high signal strength to find the network and stay connected to it. While apps like WiFiFofum find even weaker signals and are able to connect to me, I got so tired of having to sign in again and again that I finally caved, dug out my old Siemens router and set it up as a repeater. Needless to say, with the stronger signal, my iPhone now finds it easily and stays connected until I disconnect manually.
Certainly not a solution by any means, but one can never go wrong with a stronger WiFi network.

Bluetooth, for that matter, still refuses to pair up with my laptop or any other BT device. No solution for that just yet...

Mine is 6 weeks old, worked fine before. Since 18.6. after the update it can't find any wirreless network. And my friends iPhone with the old software works fine as well.
The Apple Support could not help me...

I am having similar problems. I think they tried to play with battery consumption by reduction of wifi/bt power usage + sleep mode. In that way, as many reported here, they broke down both - the battery and the wifi/bt.

bests,
audio

I've tested this with a bunch of wireless boxes now:
* Linksys WRT54GS / Tomato
* Linksys WAP54G / Custom Linux
* La Fonera / DD-WRT
* O2 Wireless Box II / Stock
* and some cheap piece of Huawei rubbish
it exhibits the same behaviour across the board. Come on, Apple!

Exactly same issues here. Fortunately my mobile account has sufficient MB's left. No matter what I tried WIFI doesn't stay active.

Despite my earlier posts... mine has stopped working again... oh for goodness sake Apple. Does it only work with Apple routers????

No, it doesn't even work with Apple routers... Airport is, too, mostly "air" 😟