It just occurred to me from mentioning ReWire in another thread that you could probably record a synth by hosting it in another DAW (like Reaper) then ReWire-ing the resultant audio back into Sonar. Just another possible solution to add to the list. 

I done a similar thing last week Sharke. It's just a pity you cannot route the individual tracks in & out of live.
I have some projects in Sonar that would take half the time to sort ready for live if I was able to just reroute the inputs and outputs per channel in Sonar to Allow me to record from Sonar to ableton direct rather than rendering stems down all the time.