jailbroken 3g wifi wont work?

[r33per]

hi guys

this is my first post and im quite new to all this but here it goes.
i jailbroke my iphone a few months back and all was well running the first update of ios 4.0 and jailbreaking.
updated to ios 4.0.1 and jailbroke and unlocked as like last time.
alls good
but after using if for a while my wifi has stopped working.
its not greyed out but i get no wifi bars and it will not pick up any signals.
im wondering if i can update to the new ios 4.1 but i need to unlock my phone as im using it in thailand and its an O2 phone.
if its not the software is there anyway of if its the hardware? has the wifi burnt out? does this happen on many iphones because if i remember correctly it did seem to get hot at the time it stopped working.

thanks in advance

chris

right, ive updated to ios 4.0.2., thought the wifi would start working after this update but it is still the same..
i think the wifi has burnt itself out, any ideas?
i also jailbroke after the update and now my phone has become useless as i cant update as no wifi and it wont read my sim because im in thailand and i need to ultrasnow it. SH#@!!
what can i do?
any ideas please? im phoneless!!