When the server side is the Linux box, i can see it trying to hand out an address without any success, showing that the request is being heard. Somehow the response back to the Macbook falls on deaf ears.
This is especially true if the machine has been sitting for a while or comes back from sleep. It will work for a few minutes and then the wireless connection will totally drop, down to zero, and nothing works on reconnection.
The only fix is to power down the Macbook and come back up. This is suboptimal.
I am going to scour the usual help sites and the apple message boards, but anything the Group Mind has to contribute would be great.