After I updated my iphone 4 to the iOS 5.1.1, I cant longer connect to any wifi/internet.

Question

After I updated my loved iphone 4 to the iOS 5.1.1, I cant longer find any internet at the wifi? I know there is a internet connection here, im at that network on my computer, so yeah... it always worked before, until i updated.  WHAT TO DO?!
i have reset all the settings, and now im trying to reset the whole iphone.. heelp

Answer 1

This happened to me the same day that ios 5.1.1 came out.  I went to iTunes to sync my iPhone, as I normally do.  I declined the 5.1.1 upgrade.  Shortly after syncing, my phone started acting slow and went to the black screen where the Apple logo usually pops up.
I turned my iPhone on and off.  Then, when I tried to connect to the internet, I was told that i had no connection.  I went into the wifi screen and it would appear to look for a signal, but never could find any wifi network whatsoever.
I turned my iPhone on and off again.  When I went into Settings, the Wi-Fi option was now grayed out and the message where the wifi network name would normally appear showed "No Wi-Fi.'
I restored every possible way.  I called Apple Care and they told me to do the same restore which I already did.
Since that didn't help, I went into the Apple store and they looked at the phone, said it was a hardware issue and gave me a "new" phone.
I really don't think it was a hardware issue, as I only had my phone since February and the wifi always worked fine.  It's too much of a coincidence that the wifi was working just fine right before the sync but failed right after th sync.
What I do believe might be related to the issue is: prior to the ios 5.1.1 update, there was also a Carrier Update which I declined.  I believe that Carrier Update had to do with adding new Hotspot features.  That option was never on my phone before, but it appeared in the General -> Network tab after I synced that day.  I think iTunes somehow automatically did the Carrier Update and that somehow screwed up the wi-fi option in combination with other unknown factors.  My phone is also unlocked from Apple, if that has anything to do with it.