5 Ghz is pretty much useless at penetrating walls.
I need to spend a bit of time optimizing my network, maybe moving my Airport Extreme to another part of the house. It's currently in a computer room on the 2nd floor and the living room is on the 1st floor on the other side of the house, the Apple TV has been struggling lately.
Home: 2006.5 iMac 20"
Me: 2010 MacBook Pro 13", iPad Mini Wifi 32GB Black, iPhone 4 16GB Black
Wife: 2011 MacBook Air 11.6", iPhone 4 16GB White
Are you backed up??? If so, why? Psyllium Fibre is not free but will do wonders!