Well after days of combing the internet and beating my head against the wall, I finally got my Netgear WNDA 3100 v2 wireless adapter working on my old Dell PC running Ubuntu 9.10 (Karmic Koala).
I am not highly technical, and am fairly new to linux, so this was a real challenge for me, so this is a kind of "Wireless for Dummies".
I will try to describe step by step for those other frustrated n00bs out there who are struggling with this.
First I installed the firmware by typing into terminal:
sudo su #
mv ar*.fw /lib/firmware
(you can copy that whole chunk and just paste it into terminal)
Thanks to Tom Wright on Linux.com for that.
then I went to http:kb.netgear.com/app/answers/detail/a_id/12115
and downloaded that file to my desktop. (For some reason this same process with software on the cd that came with my adapter did not work the driver was “invalid”).
I used Wine to “install” the drivers. Install Wine and make sure it is configured to Windows XP. It does not really install the drivers, but runs the install wizard like it was on windows and unpacks them into a kind of phony C:\ drive so you can use them. Use Wine to browse that C:\ drive and you will find a folder WNDA3100v2. Inside that folder is a folder- Driver and in that WinXP200. There you will find a file bcmwlhigh5.inf. That is the prize you have been looking for.
I just dragged the whole WNDA3100v2 folder to my desktop to make it easy to find. But, as I understand it, wherever you put it you will need to leave it in place afterward (or at least the folder with the drivers in it, not sure about that) so put it somewhere where you can keep it forever.
Then at the top of your screen, go to System/Administration/Windows Wireless Drivers (install it if you don't have it). Then click install new driver and use Windows Wireless Drivers to browse to the .inf file, click install. That's it, you should be good to go.
Somewhere in this whole process, my Network Manger Applet disappeared from the panel at the top of my screen. Just in case this happens to someone else, I installed Knetwork Manager from the Ubuntu Software Center, and was then able to configure my network so I could finally get online with my wireless adapter. One last note, my router is currently unsecured, so I'm not really all the way there yet.
It's been quite a journey, I hope my story helps someone else.