Which version of Ubuntu? Did it offer to install a custom driver from your wireless card? I ask because almost every version of Ubuntu I have used has offered to install a proprietary wireless driver. All except 9.10 which ignored my wireless card (at the time I fell back to 9.04, but now I am running 10.4).
I suggest trying the Live CD for either 9.04 or 10.04 and see if that sees the network card, and if it offers to install a proprietary driver. If so, I would suggest switching to one of those versions. (I moved from Fedora to Ubuntu years ago because I got tired to having to manually configure netwokr settings, among other things.)