ASIO4ALL No master track sound

I'll let somebody else tell you not to use ASIO4ALL.
 
What may be happening is Windows is automatically adjusting its sample rate and/or bit depth to accommodate whatever player you're using, and these new automatic settings do not match what you've got set up in SONAR, so SONAR won't play when you return to it. You could try pressing "P" in SONAR and check to see what the settings are there, then go to the Windows Sound control panel and reset them to match, but the problem will happen again every time.

Hi, +1 for Larry and Rob.
And maybe just allow "Share Drivers with Other Programs" in Preferences/Audio/Playback and Recording.
I can imagine that if you don't share, the windows player takes over and when you return to Sonar as Larry pointed out, the audio is gone. If you allow the sharing, Sonar would keep the audio in the meantime.
              ...and of course, ASIO4ALL means problems with Sonar, believe us !

I believe, at this point, I have it fixed.
 
I uninstalled the ASIO4ALL and the Realtek drivers I had installed. I setup the audio as MME and then set the buffers @ 726 (SONAR wouldn't recognize this stetting before.).  I also copied my project files to a separate HDD and deleted all of them off of my main HDD inside the SONAR program files in case the program was defaulting to old settings.  I previously had Artist and decided to go up to Professional.  I had uninstalled Artist, but when I went in to delete the old project files I saw an entire section of leftover Artist program files.  It seems I had conflicts all over the place.
 
Thanks for all of the advice and help!