I've tried all the instructions, and downloaded the updated drivers....still nothing.
 
My computer recognizes the nano, but it does NOTHING inside of SONAR. is this a driver error, or just a plain compatibility issue?
 
Couldn't Find anything on the KONTROL2 and X3.
 
Thanks in advance, and all suggestions are appreciated.

Join the club! I had a hard time getting it to work, but I must have done something right because now it's working perfectly. 
 
The most baffling issue I ran into was the dreaded Windows MIDI port limitation problem. Until I got that sorted out, I couldn't get it to work at all. Once I fixed that, then it was simply a matter of uninstalling the driver to start with a clean slate, then following Korg's instructions to the letter on the driver and applet installation. 

Have you enabled the nanokontrol as a control surface in Sonar's MIDI devices?

Korg stuff is nice but it's a pain to get set up. However there is not enough info to work with in the OP. You need to a) read the X3 manual entries on setting up your devices, b) how to set up tracks to accept signals from an external controller, c) make sure you read the documentation for the nanoKontrol to see if it has any special weirdness you have to do to make it work normally. Korg documentation is kind of weird.
 
If you've done all that describe, step by step, exactly how you hooked it up.
 
Some other thoughts...
 
Make sure you have the latest drivers for the device from Korg's site and always/only use the USB port you installed it on. If I move my padKontrol to another USB port than the one I installed it on things can get weird.
 
You say it is showing up in your devices list in preferences but it also has to be selected (checkmark beside all the Korg entries in preferences).
 
Sometimes untinstalling and reinstalling the drivers will shake something loose (and remember which port you used to install it and always use that port for the device).
 
Make sure your track has MIDI Echo enabled.
 
Oh... and welcome to the forum. ;-)

Try this site:
http://www.untidymusic.co...g-up-nanokontrol-sonar

Like Anderton I initally ran into the port limitation as well. After I took out the garbage, I was able to set up the nano as a Mackie controller and it works fine now. I don't even use the remap utility that Korg sent out. After I realized I was not going to be able to use it for a lot of the vsti instrument controls it became easier to use. :).

I have one of the original NanoKontroller's.   I bought it as a backup as my BCF2000 is flakey and has failed to work a couple of times.  It was a Musician Friend's stupid deal of the day.  
 
I had the port limitation problem, too, initially.  It is set up as an ACT controller and works OK.  Fortunately the BCF2000 hasn't crapped out since I got the Korg.

I just remembered another thing that prevents my padKontrol from working (not the same device but this might help).
 
If I open Sonar BEFORE turning on or plugging in the padKontrol it doesn't work. So I have to make sure that the device is plugged in, turned on THEN turn on Sonar. That one drove me nuts.
 
Also on my computer any time I plug in any of my MIDI controllers Windows shows a little icon in the taskbar that lights up when I press a key/pad on the device. I'm assuming that is standard for all Windows installations. If you see that icon (it's a little grey square with two red circles that light up when there is MIDI activity) and the it lights up when you press a key on the nano but you still aren't getting any activity in Sonar you probably haven't set something up in Preferences or on the track correctly. Check the Sonar user guide and the Korg manual (or their website/forum) for instructions to set everything up.
 
Cheers.

I can confirm that these are frustrating things to get working. In my case I could use the Mackie Control surface OK, and the buttons, faders and rotaries on the nano kontroller worked as you would expect. But as soon as I tried to use the Act midi controller surface everything fell apart and the midi learn function wouldn't work properly. I managed to get mine working fully by following a You Tube video ( Google : "using the korg nanokontrol 2 -- part 02" ). This results in re-setting the cc numbers on the controller, and I think taking away any conflicts probably did the trick for me ( but I can't say for sure ). Note that the video is not specific to Sonar, but the way it sets up the Korg is key.
 

I know you have to set the nanokontrol to scene 2 for it to work...