At my wits end since this problem just started a few weeks ago.  
Every time i fire up Sonar X1 Producer to record something, it works fine at first.  However, as soon as I hit stop or pause, the recording signal gets cut off and I have to power down/up my external soundcard (actually a Fractal Axe-FX guitar processor if anyone is familiar) and Sonar to get it working again.  Playback works fine at all times.  It's just recording.  Latest driver and audio format(48K) is correctly chosen in Sonar.  Like I said, all this has worked in the past.  I also have a version of Audacity on my computer, and when I use it, everything works properly so I know it's something within Sonar.  
 
Any suggestions?   

Are the audio settings in Sonar ok? Is the audio driver sharing checked? You could reinstall Sonar. Is the audio interface selected as the default audio device? Is asio4all installed ? I think it should be uninstalled.

Yes to all except no asio4all.  I was leaning toward a reinstallation myself, but came here first to see if anyone had another alternative.  

Are the windows audio settings the same as sonar?
 
Are both windows and sonar set to share audio drivers?

Yes, and yes. 
 
I spent hours doing a complete uninstall/reinstall last night.  It did not help the problem at all. 
 
Have tested with a copy of Audacity I have as well as Reaper and both of these programs do not shut down when I stop/pause after recording.  Only Sonar.  Very perplexed.