I can call up a synth- play it live fine- can see it on the Midi track and the output channel - control it, etc. - it's happening in the Sonar I record some on the Midi track - the Midi channel shows it's happening- but the audio channel will not receive it. Any ideas? Thanks.

When recording, have you armed your synth track beforehand ? (select the little red dot in the track either in the track view or the console view)

Sonar will only record the tracks that are armed when you hit the main record button in the control bar.

Silly question, do you have any pre roll enabled in Reason, or count-in measures in SONAR? If so get rid of that as well, it can cause problems.