HELP - lost sound

This system has been running GREAT.  I love it!  But in my rush to shut things down - I shut down my Presonus Firestudio while a cakewalk project was still open and clicked on something without really reading it (I was in a rush - thats ALWAYS trouble).  So I restarted my system - and now I have no sound.  I can see the meters registering on playback - but can't hear anything.  If I try to play the midi tracks out thru my keyboard - that works - but I can;t get any of my audio tracks (and most of waht AI do is audio).  Someone help me please ! ! !
 
Thanks
 
Using Presonus Firestudio - Windows 7 64 bit; Sonar producer 8.5

Go to Options>Audio and make sure the device is listed in the Drivers tab (and all others disabled unless you have a reason to keep them active), and the Firestudio is the only device used for Recording/Playback Master. Then check the output of any tracks/buses that were routed to the Firestudio before. Sonar may have switched to another audio device after you switched the Firestudio off and you will have to manually change the settings back to where they were before.

This is another good reason to use a Master Bus. If tracks/buses are routed to a Master bus and ONLY the Master Bus is routed to the Audio Interface, then you only have to change the output of the Master Bus if something like this happens.