Weird issue today.  I was doing some editing of WAV files.  I started to group some edited clips together by using "Bounce to Clip."  A pretty common task I've done many times before.  But today, it yields a completely muted clip.  OK ... I thought maybe it was something with just one track, so I tried to cut out a piece of other tracks and bounce it to clip--same thing.  It renders a completely silent track with a perfectly flat waveform. 
 
Any ideas how to get back to normal?

Uhm ... weird.  I decided to try it again ... because I'm insane like that (ya know, doing the same thing over-and-over and expecting different results).  Well, it all seems normal now.  WTF?  I'm sorry if I wasted your time to whomeve might read this (now ... how do I delete posts?).

Glad things are now working.  There have been two other threads in the last day regarding bounce to clips so I was going to post links to them in case they were related.  They're all different issues but it was the recurrence of the function as a topic that looked suspect.

I had the same thing the other day. Restarting Sonar fixed it. Maybe it's a Newburyport thing?

I had the same thing last night whilst trying to bounce to clip and also doing a Melodyne region FX - flat line and no audio. 
Restarting Sonar fixed it but it's something worth keeping an eye on !

I've seen this occasionally, too.