I'm using Sonar X3 for mastering.  I have about 5 songs loaded in the project.  I'm finished with my tweaking.  However, when I export them one at a time, 4 of the exported songs have silence at the end.  Sonar continues to export until the end of the longest song even though it is muted.  Is there a work around to stop this behavior?  Naturally, this adds an additional step of clipping the ends of the other 4 songs via more editing.

Yes, you can:
 
1: select all (CTRL+A)
2: select by time (edit menu) and set the first and last bar you need
3: export.
 
Bye,
 
Giorgio

You may also want to "apply trimming" to each clip prior to export.

Anderton
You may also want to "apply trimming" to each clip prior to export.

I do this ^

So select time first then export the individual track.  Repeat for each export.  Thanks.

I'll do this too.  Thanks.
 

Anderton
You may also want to "apply trimming" to each clip prior to export.

May I ask how you do this or be pointed to a reference please Craig.
 
P.S 
Are you the Craig Anderton who wrote "Recording for musicians" way back in the early 80's?
 

jmasno5
So select time first then export the individual track.  Repeat for each export.  Thanks.

I usually export beyond the end of the song, (because I've chopped off tails too many times...) then open it up in Sony SoundForge - I trim there, apply any fades, and export various formats from there...
 
But that's me....

I use one project just for mastering backing tracks for live play, for leveling etc. Hundreds of them. The workaround I use for your problem is I move each track to the same finish point, so that all tracks are essentially the same length. Then for bouncing out, just select the track I want out, and it bounces out from the beginning of the selection to the end. I have a marker set for the last 'crash' or note of the track, for alignment.
 
Works well, although I'm sure there is a better way.
 
Dave

For the OP.
You can see the progress bar with the x at the end as your mix renders. Click it.  A dialogue will appear "do you want to keep the file" click 'yes."
 
Use this for extra long takes automated or muted tracks or lanes still being exported and you can trim the mixdown.
It is the only task Sonar allows you to do when exporting.
It is a function,rather than a work around for that exact situation you have.