[X4U] Keep Airport connex alive during sleep/wake?

[Anne-Marie Concepcion]

One of the computers in my 5-mac network always loses its Airport 
connection when it goes to Sleep. When you open the Powerbook again, 
you have to go to the Airport menulet and choose the name of the 
Airport connection again to regain access to the network.

None of the other desktop/laptop Macs in the network has this 
problem. Airport connections are maintained when they go into sleep 
mode and woken up again.

I've ran disk utlity on this Powerbook and I've upgraded it to Tiger 
10.4.3 (from Panther) and the problem  persists. Any suggestions?

Thanks
AM