Macbook continues to disconnect from airport express..Help

It has been doing this since they day I got my MacBook. I have my network set up in the preferred networks and is also set to manually connect. However, every day, repeatedly my computer will disconect from the network.

Pretty much, the my wireless icon will go dim and not be connected to a network. When I click on it, my network name is there, select it, and it connects right back to the network.

Why does my airport card continute to disconnect with my airport express router? Is there a fix for this?

Thanks

Did you install the firmware updates? I think they have fixed this issue already.

Yes the firmware is up to date.

Also a problem that I will have is that my computer will stay connected to my network, however it will not be able to have any activity. Also, Airport Manager will not see my airport express when this is occuring.

I have to unplug the power from the airport express and then this resolves the issue?

I have a similar sounding problem, i'm on an iBook G4 and using a D-Link Wireless router. AGray; how far away are you from your Airport when using your macbook? I was speaking to a friend the other day who also told me that some rooms in houses (like bathrooms) sometimes have a special insulator/foil sheet in the walls around the room which wireless signals have difficulty passing through. Just some suggestions