ok, i had to sign up just to post this in the hope it helps others.
my problem was the wifi button wouldnt turn on no matter what i did, i switched it on and it would switch off. anyhow...people suggested to root the phone then rename a wifi file and it will fix the problem. again this didnt work, i didnt have a clue on how to root, but after 5 hours i feel like an expert hehe. i managed to unroot the phone back to stock.
i got speaking with a fella from another forum, he suggested dialing *#0011# and enter the service menu, from there hit the menu button and choose wifi, then turn off WiFi Power Saver Mode. i did this and exited. i then tried the wifi, it never worked but i then re dialed *#0011# and entered the service menu once more, hit the menu button and choose wifi, then turned on WiFi Power Saver Mode. after doing this it has worked flawlessly ever since. doing this resets the wifi cache. so in short disable WiFi Power Saver Mode then exit, then enable WiFi Power Saver Mode again.
i thought i would post a solution that worked first time for me, like i say i tried rooting and unrooting but nothing worked. i only hope this will work for you.
please reply if this helps you in anyway so others can benefit.
thanks.