01-01-2011 10:17 AM
i think totally this is not answer of this issue total.there is some thing other problem.
As I have determined, the grey wifi icon does NOT mean the device will not use wi-fi to browse the internet. It only means the blackberry email is not available via that connected wifi access point. i have been able to surf using the blackberry browser when connected to an access point with a grey wifi icon; verifying this by disconnecting the Mobile Network (home --> network connections) while surfing.
01-17-2011 05:06 PM
This happened to me just yesterday, i've picked the bones out of many of the solutions here and this is what's worked.
Delete all WiFi Profiles and turn WiFi off
Setup > Options > Advanced Options > Host Routing Table > WiFi 
Menu > Register Now
Wait 15 minutes and turn WiFi back on
Join your network wait 5 and everything should be fine and the WiFi icon turnes white and you get the green tick
Mine was working fine until i got bored and run a dodgy app that accessed the web, i tried everything including rolling back the OS and restoring, I tried the above and bingo.
03-23-2011 08:53 AM
I have tried all these steps and nothing ...
I have Blackberry Bold - and i cannot access my home wireless wifi (grey icon).
if i disconnect from the mobile network (in order to test it - thus disabling the 3g) than i cannot surf the web.
The interest thing that on a different wifi network, the same device works fine.