James,
I agree that you won't be able to save a Sonar file to an earlier version, as you can with a lot of software. I think our friend from New Jersey has the right idea (as usual).
The export each track as a wav file method is not really that tedious. Here's a tip:
While in Sonar, slice all the tracks in the same spot timewise (like a second or two before any music starts). Delete the silence before. Export your audio.
When you bring your individual tracks back into your PA9 (or Cubase, or Pro-tools) project, they'll all start at the same time (in Sonar, it's wherever you have your cursor). Or, arm all your tracks and record a cowbell click or two at the beginning of each track before you export. Then zoom way in on the waveforms and line up the peaks after you import.