Well it's certainly a first for me - Windows can find a driver and Linux can't? It may be that wireless was connected when you first installed Ubuntu and you ticked to ignore disconnected hardware. Have you been into the Hardware setup page to see the status of the ethernet?
i have installed recently windows 7 and ubuntu 10.04 on the same hard drive partitioned. The thing is that on windows 7, ethernet works properly and gets connected to the internet. In ubuntu, however, when i plug in the ethernet cable, nothing happens, i can't connect to the internet by ethernet, only wireless.