Unable to connect Wifi after iPhone 3.1 upgrade

[MADGE25]

Hell friends,
My uncle gifted me a new iPhone 3G. It don't have any problem until last 2 days. Before 2 days I upgraded my iPhone 3G with 3.1 firmware. since then, my iphone unable to connect to WiFi. I tried to restart my iphone, but it doesn't work out. I don't know what happened to it. Please help me.
Thanks in advanced.

[Gonzo]

From your information it seems that there is no problem in your iphone. I think your Wifi router is not working properly. First check whether your wifi router is working properly or not. You can check it by connecting to wifi router with your wifi enable laptop or mobile. If you are not able to connect to your wifi through laptop and moblile, then there is some problem in wifi router. Just try to Restart your Wifi router and check whether you get the same problem or not.

[Pugsly]

I think there is need to do some setting in your iphone and wifi router to fix this problem. You can use following steps to make some changes in your iphone and wifi router.
1.First you have to make setting in your wifi router. Try to revoke the IP Lease issued to the iPhone by going in admin program in wifi Router.
2.Now reset the network setting on iphone. You can do this in following ways.
First go to settings option -> now select General option-> choose Reset option -> now click on "Reset Network Settings" option.
3.Now go back to your iphone setting option -> now click on WiFi setup Network Connectivity -> now again go back to router and set the iPhones IP address lease to never to expire.

[Regina]

I also had the same problem then I used following steps and it works for me. I think you aslo try these steps.
1.In the iphonec click on Settings option > select General option > click on Reset option > now click on Reset Network Settings option.
2.Now check whether your iphone display Wi-Fi address or Bluetooth address.
3.If it shows Wi-Fi address then you can now able to connect to wifi using iphone.

[Simond]

You are getting this problem due to 3.1 upgrade. I think this update is not working properly with your iphone. In this case you have to install older version of upgrade in your iphone. You can do this using itunes. Connect your iphone to itunes and look out for older version from apple store. Now select that version and click on restore button. After this you will not get this problem again.

[Halina]

From your information it seems that there is some problem in your iphone's software. You have to restore your iphone again to get rid out of this problem. If you don't know how to restore your iphone then use following steps.
First connect your iphone to PC -> now format your iphone -> open itunes application and click on Restore button.
After this if you still have the same problem then you have to contact your nearest apple store to fix this problem.