First Go At Vocalsync, No Joy.....

Last night, I got my first chance to try out VocalSync, but I must be doing something wrong, because I'm getting a loss of all sound from Sonar.
 
I have two vocal tracks.  They were initially two different takes of the lead vocal.  One track I edited with Melodyne, to turn into a Lead harmony track.  Basically deleting phrases and adjusting the pitch.  Afterwards, I bounced the edited track down.
 
Next I right clicked on the edited track and created a region effect with Vocalsync.  I chose the lead vocal track as the reference track.   After a few seconds, I got the two tracks and the Vocalsync editor knob.
 
Here's where the problem occurs.  As soon as I hit play to listen, the level meters for the harmony track goes off the scale and freezes, and the sound for everything disappears in Sonar.  I hit play, and hear nothing, from any of the tracks in the project.   If I cancel the Vocalsync edit, all the sound returns.
 
Any ideas?

Thanks.   Yes, I watched that video before trying out vocalsync last night.  In the video, everything worked as advertised.   Unfortunately, It did not work that way for me.

That's odd. Mine works fine. Are you running 64bit? Sounds like a similar problem I get with Channel Tool sometimes, and I suspect it's a 32-bit plugin issue inside my 64-bit environment (though I have no proof of that).
 
Just a tip, once you do have it working, it's still best to manually chop up the vocals and line them up as close to the original as possible, including a little time stretching if needed. Then bounce the clip and then only apply vocal sync as little as possible.  

Didn't have a lot of time to experiment last night, but I made a little progress.  
 
Last night, I tried reversing the track selection, and vocalsync worked correctly.  Instead of creating a region effect on the harmony track and using the lead vocal as the guide,  I created the region effect on the lead vocal track, then selected the harmony track as the guide.  This worked.  Not sure why it froze when doing the opposite.