My Airport is new but does not detect wireless networks

Hi

I have a PowerBook G4 Titanium machine and everything works fine, in fact, the Airport is brand new and a few days ago when installing the operating system Mac OS Tiger I was fine but now I do not detect wireless networks to the computer ancender Airport is turned on atumomático mode but does not detect a single network around my house and my neighbors, that is completely foreign.

I was checking the card if he had any calble disconnected or something similar but everything is fine, in fact when I read the system and network information tells me that the Airpot is running and connected from computer to computer. No that's what happens, I have tried many things in them created new networks with user name and WEP key, WEP 40-128, WEP personnel, etc, etc. Does not work even one.

I would greatly appreciate if I can help with this problem, it is possible that this is in a default configuration that is not really but it can be.

Thank you very much and I hope your help. ;-)