computer freezes configuring wireless eth card

Hi, may I know what version of ubuntu are you using?

In any case, there are still some issues with some ralink devices if I'm not mistaken. I'm not sure what driver your hardware is using but in my case, it's an rt61-based card. The default/included Ubuntu driver doesn't work so I had to compile it myself.

I've had similar problems with a Linksys wireless card in Feisty and different problems with that card in Edgy.

I had an older Q-tec wireless b card working in Edgy using ndiswrapper and the WavePlus drivers however it suffered from numerous dropped connections. Tried a Linksys WMP54G v4.1 (RT61 based) but I could not make it work with ndiswrapper & the Linsys or ralink drivers.

After upgrading to Feisty, booting with the Linksys card installed would cause the computer to freeze during start-up before the login screen. I swapped back the Q-tec card and was able to boot, but was unable to get that card working in Feisty.
However, poking around with modprobe I noticed that the RT61 drivers were already loaded by default. After completely removing ndiswrapper I was able to boot into the recovery console with the Linksys card installed. At that point ifconfig showed the interface ra0 present. I manually edited the etc/network/interfaces file to add ra0 with dhcp, my network SSID and WEP key, and I was able to connect to the network.

I could now boot normally however the computer would freeze after a few moments, just as Network Manager became active. Removing Network Manager bought a few minutes extra but the computer would still freeze after a few minutes, or as soon as I tried to use an network application. I also got freezes using the the System/Administration/Network tool to bring up the interface - exactly the same as Joe posted, ra0 shows not configured and as soon as I click on properties the computer feezes. however with manually created config files I can go to the terminal and issue "ifdown ra0" followed by "ifup ra0" and then everything is fine.