SE W715 Wi-Fi Problem

Well I've searched for threads talking about this but I didn't find any so made a new one.
So I bought a new SE W715 a few weeks ago and all worked just fine!I even tried connecting it by WLAN to my wireless internet and it worked, once, now everytime I turn on my Wi-Fi it just keeps searching and it doesn't find anything :( I've tried everything but I can't see what the problem is and it also stars by itself when I turn on my cell phone.
I would appreciate your help thank you :D

By the way sorry for my english!

i think u should try to download the updated software for that mobile..go to sony ericsson site and select your model,and you will read informations to update the software of the mobile..it may work..