robert_e_bone
I saw some older threads with this type of behavior.
 
Are you by chance using ASIO4ALL?  
 
Also, what driver-mode are you using, what audio device is Sonar using, and what is your Windows default audio device set to?
 
Bob Bone
 

No. I'm using the latest Echo Audio drivers/firmware.

OK - how about your Windows default audio device and driver mode?
 
Thanks, I am just trying to get up to speed on what and how your are running.
 
Bob Bone

Do you have another piece of software, like iTunes or WMP or an internet browser, running when you load Sonar?  Sometimes, those programs hold your audio device hostage and require Sonar to take control of it by starting the audio engine.  I think there is a preference that allows sharing the audio device with other programs.  Not sure if it should be checked or unchecked to fix your problem.

Well, the hijacking of audio devices will only happen if other applications are set to use the same device as Sonar.  
 
I have the Windows default audio device set to the on-board sound, and ONLY Sonar and music applications use the audio interface.
 
Bob Bone
 

Try checking "Always Stream Audio through FX" in Prefs--->Playback & Recording. That may well help as it should keep the engine running for you in case it's stopping on load.
 
Used to be "Always play fx tails" in earlier versions.
 
HTH

Are you saying that when you hit spacebar/play, there is no audio? The audio engine does not engage itself?
 
Perhaps you have another application open that is using the audio engine, even an internet browser.

That's what I was wondering.
 
I was thinking maybe the Windows default audio device is set to the audio interface, and some application is grabbing it.
 
Bob Bone
 

Just a shot in the dark, but what happens when you press the play bar?
 
By default, when you open Sonar, the Audio Engine button is not lit, but lights as soon as you hit play, or press the space bar.

My default device is a Roland Quad Capture but the Sonar device is an Echo 8Pre.  This happen on a fresh boot with nothing else open.  I don't have ASIO4ALL loaded.

Thanks for the explanation - It is my understanding that only 1 ASIO driver can be present and active.
 
Do you have both devices set to use ASIO?
 
I always use WDM drivers for Windows sounds, and actually use my on-board sound chip for the Windows default audio device.
 
Edited - sorry got it backwards.
 
Please, for a test, remove the Roland, and set your Windows default audio device to your on-board sound.  This is just to test the effect on your issue.
 
Thanks, 
 
Bob Bone