Last night my son was working on Sonar X3. Being young of course he does not save frequently.
He came down stairs in a panic saying Sonar was frozen and he could get it to do anything and he had been working for 3 hours.
It was not that Sonar was crashed, it was that some confirmation windows had popped up during his session and they were stuck in the Sonar work space and they were unreachable with mouse or keyboard. Could not do anything from task bar either. I have had this in the past, but because I am a frequent saver, I never lost too much work. In essence the PC needed a confirmation to continue, but there was no way to confirm.
What I discovered is that you can control-alt-delete and open task manager.
In the process tab, you will see Apps. Sonar should be one of them.
Left click on the less than sign to the left of the App name.
Now right click on the App that appears right below the main header.
You should now see options> Switch to, Bring to Front, minimize, maximize, end task.
In our case minimizing and then maximizing cleared the stuck confirmation window and we were able to save.
I also went into preferences and enabled auto save.
Hope this makes sense and helps.
JR