I have a 10.6.4 white Macbook. I just got it last christmas. I recently purchased an Airport Express. I use it for my Macbook and my 10.4.11 desktop iMac (I don't know which version it is, but it has a built-in iSight camera).
For the first few months both computers connected like they should and I was able to use my Macbook all through the house. Now, my desktop iMac can still connect just fine, but my Macbook barely connects at all. The only time I can get it to connect is if I'm in the same room where the Airport is located, and even then it doesn't connect sometimes.
I'm guessing my Macbook is the problem. But I don't know what to do about it.
Any advice?

Simple solution... buy a pc... then everybody could answer your question.

if you can still, return it and get a Linksys Wireless-N router. I have a MacBook and it works great.