iPhone 4 wifi issues?

[NicolaW]

Hi, I just got my dad's old iPhone 4 unlocked by apple today.
But although it connects to the Wifi when I'm next to the router, it can't find it about 4 metres away.
However, I have a 3Gs which is connected fine, the same distance away.

Any suggestions on why this is?
I've already reset the phone
and turned the router on and off

Thank you

EDIT: Any input is much appreciated!

 

[edk]

same issue (kinda).

i've rebooted the router (n mode) and reset the iphone... but basically, wifi signal strength is much less vs my older iphone 4. A real shame. I can't surf while sitting on the loo anymore!!! Apple you MUST SOLVE THIS!