Networking :: Wireless Network Times Out - Will Not Restart Without Reboot

I had been manually starting my wireless network with "sudo iwconfig wlan0 essid "my wireless router id". The network would start and work flawlessly for weeks at a time. I can't ask my wife to find the essid in the terminal and then start wireless manually when I'm not here. She hates and fears the terminal. So I downloaded gnome network manager for a point and click interface on gnome panel.The network would start fine but shut down after anywhere from one to six hours. It would then refuse to restart manually or otherwise. I completely uninstalled network manager and tried wicd instead. The same basic problem is happening. The network will restart if I reboot the computer. My system:

Desktop computer acting as proxy server for the internet. Internet connection is by a dial up modem. This computer uses a wireless pci card connected to a dedicated hub. This is for file sharing via nfs. The OS is ubuntu 9.10. My wife's computer sharing the internet using a proxy to my computer. File sharing via nfs and a wireless card. Also running ubuntu 9.10. This same basic system worked flawlessly under Ubuntu Hardy.My desktop was updated recently with new hardware which created the need to move to Ubuntu Karmic. Some hardware was too new for hardy to deal with.