I'm running Ubuntu 12.04 and after searching these forums unsuccessfully, I have installed the driver for my AE1200 and it is working correctly.
Here is how I did it:
First, install ndiswrapper and be sure to install ndiswrapper-common and ndiswrapper-dkms as well.
Then, download the XP driver for the device: http://support.linksys.com/en-us/support/adapters/AE1200
Extract the zip and
cd to the folder (probably xp). If you attempt to install the driver with ndiswrapper at this point, you will receive the "couldn't find section "Linksys_AE1200.files.NTamd64"" error. To resolve this, edit the bcmwlhigh5.inf file. Find the section that looks like this:
Underneath it, add this:
Save and close.
Then, if you've already attempted to install the driver with ndiswrapper you'll need to remove it, run:
sudo ndiswrapper -e bcmwlhigh5
Then do the install again:
sudo ndiswrapper -i bcmwlhigh5.inf
sudo ndiswrapper -l
Now plug in the USB device and the blue light should come on.
I could be wrong, but I think this means whoever wrote these .inf files forgot to include those lines, which I find funny.
**Update for 12.10- If you install ndiswrapper-dkms it will fail and you will start getting system errors. Follow the solution here to resolve: https://bugs.launchpad.net/ubuntu/+source/ndiswrapper/+bug/1023645/comments/3
As a side note the source code he refers to is everything in the "driver" directory of the extracted tar.gz
In addition, you will also want to run:
sudo dkms remove ndiswrapper/1.57 --all
sudo dkms uninstall ndiswrapper/1.57