Thanks scook. the problem was that I had my AD2 kit mapped to separate tracks (all synth audio outs rather than simple instrument) the audio recording function only works with simple instruments.
 
Just seen a groove 3 tutorial on AD2 which  shows drum hits being automatically recorded to audio this doesn't happen for me.
the groove3 video is using pro tools for the tutorial, is this functionality disabled in sonar?
 
btw - when I say "drum hits" i mean triggering ad2 kit pieces either by clicking or by using midi keyboard.
 
if you look at the bottom left of the ad2 audio interface you will see the words audio recorder and a light and an arrow - in the turtorial whan the drum hit is recorded the light goes red and at the end the arrow points to the word WAV which can then be dragged and dropped as an audio clip. This is the stuff i'm talking about.
 
cant find any additional set up infor anywhere to enable this.
 
thanks
Colin 

It works in SONAR. I tested it by clicking on a kit piece and using a MIDI controller (input echo must be enabled).
Here is a simple test

• CTRL+N for new project
• Add an audio track
• Add AD2 as a instrument track
• Switch to the kit view in AD2
• Click the kick drum - the Audio Recording in AD2 should flash red and a wav icon will appear to the right of the red light
• Drag the wav icon to the audio track
• Play the clip

 
Don't forget you can also directly record audio inside SONAR using synth audio recording http://www.cakewalk.com/Documentation?product=SONAR&language=3&help=NewFeatures.037.html