[other] losing ability to connect to server

view story

http://ubuntuforums.org – I have a 10.4 server with an rt61pci card that i have configured manually using wpa2. The connection works fine for a while; however, after the server's screen saver comes on, I can no longer access the server remotely. I can't even ping it. If I log onto the server, I can ping the router, internet, etc. -everything looks great; however, the only way I am able to ping/access the server from another box is by restarting the networking service. The machine is configured with a static ip address and I did notice that the wireless router shows the mac address with a IP instead of the one (HowTos)