Wireless Network - very poor reception!

First I would try running the "Repair Permissions" located in Utilities. If you live close to a Apple Store then taking it in would be the quickest solution. Even an Apple Reseller should be able to check your card. My wife had some trouble, at the Apple Store they have a wireless setup, so that will be an automatic check. Then you can begin with rule out ht obvious.

 

Make sure the card is properly installed, make sure the wire is connected and it is securley fastened postion, apply pressure but not too much to break it, sometimes people dont snap them in all the way and they are loose and get poor reception try that and if it doesnt work go to a local apple store or test it out on a friends wireless network to see if the routers faulty.

 

I was having the same issues with my airport base station...I figured out it was because it was in such lose proximity to a metal table...actually under it. I thought it was because of the house walls, but after moving it downstairs, I realized it was the metal abdorbing the signal. Gobbldygook.